The protests against President Aleksandar Vucic of Serbia had been growing in intensity and size when an unusual guest showed up in its capital this month to meet with the embattled European leader: Donald Trump Jr., the oldest son of President Trump.

The quick visit by Mr. Trump, which included a meeting with Mr. Vucic to talk about U.S. foreign aid to Serbia, came as the Trump family and Jared Kushner, the American president’s son-in-law, were moving ahead with plans to build a Trump International Hotel in Belgrade, the first such property in Europe.

The hotel is slated to be built atop the site of the former Yugoslavian Ministry of Defense headquarters, which was bombed by NATO 26 years ago on land now owned by the Serbian government. Opposition leaders in Serbia have criticized the agreement and called for it to be terminated, raising the prospect that the deal could be scuttled in a change of power.

Mr. Trump used the visit as an opportunity to express his support for Mr. Vucic — a trip that offered perhaps the most explicit mixing so far in President Trump’s second term of U.S. foreign policy and the Trump family’s financial interests.

On Wednesday, the Serbian Parliament accepted the resignation of its prime minister, bringing down the governing party and forcing Mr. Vucic to form a new government or hold new parliamentary elections later this year, creating more uncertainty there.

A spokesman for Donald Trump Jr. dismissed any suggestion that his visit created a conflict of interest. The spokesman said the trip had been driven by a plan to interview Mr. Vucic for Mr. Trump’s podcast, not to step into foreign relations issues or the real-estate deal.

“Don hosts one of the biggest political podcasts in the world and was in Serbia strictly in his capacity as a podcast host for an interview,” Andy Surabian, the spokesman, said. “He was in and out of the country in less than eight hours and at no point had any discussions with anyone relating to Trump Org.”

The visit, according to two individuals briefed on the plan, was arranged by Brad Parscale, a former campaign manager for President Trump.

Mr. Parscale, an executive at a conservative podcast and radio broadcasting company, also founded a political campaign consulting firm. He had pitched advising Mr. Vucic during his 2022 re-election campaign, but has asserted he did not get hired.

Mr. Vucic is now facing one of the biggest tests of his nearly eight years as president. Protests against his administration erupted in November after the collapse of a concrete structure atop a railway station walkway that killed 15, an accident that demonstrators blamed in part on government corruption.

The visit by Mr. Trump last week had brought a brief pause in those troubles and immediately became national news in Serbia, with Mr. Vucic and his top advisers pointing to it as a sign that the Trump administration supports Mr. Vucic, despite the growing protests in the streets of the capital.

“A cordial conversation with Donald Trump Jr., the son of U.S. President Donald Trump about bilateral relations between Serbia and the U.S.A. and current topics that shape the global political and economic scene,” Mr. Vucic wrote in a social media posting after the meeting.

Marko Djuric, Serbia’s foreign affairs minister, added in a television interview after Mr. Trump’s visit that the presence of President Trump’s son “provides great momentum for an excellent start to relations with the new administration.”

Others in the country had quite a different view.

“The son of President Trump is here to try to give Vucic a helping hand,” said Dragan Jonic, an opposition-party member of Serbia’s parliament. “It is obviously a conflict of interest, as Vucic is trying to hold on to power and the Trumps want to keep their real estate deal alive.”

Mr. Vucic’s government signed an agreement last May with Affinity Global Development, a company set up by Mr. Kushner. The company plans to invest $500 million to build a 175-room Trump hotel with 1,500 luxury apartments and other amenities at the former defense ministry site in Belgrade.

“We are thrilled to expand our presence into Europe,” Eric Trump, another of President Trump’s sons, said in January, when the inclusion of a Trump International Hotel to the project was first publicly announced. Eric Trump is the lead family member running its real estate company.

But Donald Trump Jr. is also an executive vice president at Trump Organization, which operates the family’s hotels, golf courses and other assets, and is helping with planning for the Serbian hotel project.

Two individuals who had been briefed on Donald Trump Jr.’s travel, but who spoke on condition of anonymity because they were not authorized to discuss it publicly, said Mr. Trump was not paid for taking the trip. But his airfare, and that of his girlfriend, Bettina Anderson, was covered by Mr. Parscale, who has a business partner based in Serbia. Mr. Parscale declined to comment or to disclose the name of his Serbian business partner.

Virginia Canter, a former ethics adviser to the International Monetary Fund, said that Donald Trump Jr.’s meeting with the Serbian president was reminiscent of activity by Hunter Biden, who was accused by Republicans of leveraging the position of his father, Joseph R. Biden Jr., as vice president to make lucrative overseas business deals.

“It is kind of the height of hypocrisy that they were concerned about Hunter Biden’s foreign work,” said Ms. Canter, who also served as an ethics lawyer in the Clinton White House and now works at a nonprofit group called State Democracy Defenders Action, which has been critical of Mr. Trump.

In Ms. Canter’s view, the conflict of interest in Donald Trump Jr.’s case is more explicit.

“Don Jr., as a surrogate for his father, is using the public office of the president of the United States to help the president of Serbia stay in office — while furthering the Trump family’s personal financial interest,” she said. “It is unethical. It’s offensive.”

It remains unclear how much Mr. Trump’s presence in Serbia may have helped Mr. Vucic.

Several days after the visit, the streets of central Belgrade were jammed with more than 100,000 demonstrators for what organizers called one of the largest protests in the nation’s history.

Mr. Vucic’s government offered the Trump family a deal last year, as President Trump was running for re-election, to gain access to the prime real-estate development site in the middle of Belgrade.

The government is leasing the site to Mr. Kushner’s real-estate partnership for 99 years, according to Serbian officials. Affinity Global Development, the Kushner affiliate, in return has agreed to build the hotel and luxury apartments in a partnership with Mohamed Alabbar, a business executive from the United Arab Emirates.

Donald J. Trump, before he was first elected president and while he was still running the family real-estate business, had first considered building a hotel at this exact site in 2013 and associates of the Trump Organization traveled to Belgrade to inspect the location. The project did not come together before Mr. Trump’s election in 2016, but Mr. Kushner revived it last year while Mr. Trump was running again for office.

The hotel project had generated smaller scale protests in Belgrade even before the fatal rail station canopy collapse late last year.

Opposition leaders like Mr. Jonic argued that the former Ministry of Defense site was symbolic because it was attacked by NATO forces led by the United States in 1999 when Serbia and its neighbor Montenegro were part of Yugoslavia. It should not be turned over to American real-estate developers seeking a profit, the opposition leaders said.

“Can you imagine an American president, any president, giving West Point as a gift to an offshore company, only to demolish it and build a hotel?” Aleksandar Jovanovic, a member of Serbia’s parliament, said last year as the deal was being negotiated, referencing the U.S. Military Academy.

“One would have to have a vivid imagination to imagine that. Unfortunately, what is unthinkable in America is a tragic reality in Serbia,” he said at that time.

Donald Trump Jr., in addition to being shown the layout of downtown Belgrade by Serbia’s president, conducted a nearly hourlong interview with Mr. Vucic that was broadcast in recent days on Mr. Trump’s podcast, “Triggered.”

During the conversation, Mr. Trump compared the protests in response to the November rail station collapse to criticism of the Jan. 6, 2021, attack by his father’s supporters on the Capitol in Washington.

“It was later weaponized,” Mr. Trump said during the interview, before continuing with theories raised by Trump allies related to events in Washington “like our, you know, Jan. 6 turned into something that it wasn’t, to incite potentially even a revolution.”

Mr. Trump and Mr. Vucic also talked about Russia and the war in Ukraine and Mr. Vucic’s work with President Trump during his first term.

They both asserted separately that funding from the U.S. Agency for International Development, which the Trump administration has slashed over the last two months, had been improperly used by some nonprofit groups in Serbia to play a role in the protests, although neither offered proof of this allegation.

The Trump family’s evident support of Mr. Vucic is much appreciated, the Serbian president made clear, adding that he believes it is part of the reason President Trump is so popular in Serbia.

“This was the country where Trump was enjoying the biggest popularity in the entire Europe by far,” Mr. Vucic said. “I’m not flattering him or I’m not flattering you. I’m saying what people here think.”

Andrew Higgins contributed reporting.

President Trump said on Wednesday that the Iran-backed Houthi militant group in Yemen would be “completely annihilated” by U.S. military strikes and warned Tehran to “immediately” stop supplying it with military equipment and general support and “let the Houthis fight it out themselves.”

His remarks, posted on social media, came as the U.S. military continued a wave of attacks on Houthi targets in Yemen as part of what American officials said was an effort to stop the militant group’s attacks on commercial ships in the Red Sea.

“Tremendous damage has been inflicted,” Mr. Trump said of the effects of the strikes, which began on Saturday. He added: “Watch how it will get progressively worse. It’s not even a fair fight, and never will be. They will be completely annihilated!”

Earlier on Wednesday, the U.S. Central Command posted a video showing American fighter jets shooting down Houthi attack drones. The military has been striking the group’s training sites, command centers and weapons facilities since the weekend in what it says is an attempt to restore freedom of navigation in regional waters.

The Houthis have been targeting Israel and attacking ships in the Red Sea in solidarity with the armed Palestinian group Hamas, which is also backed by Iran and led the Oct. 7, 2023, attack on Israel that set off the war in Gaza.

After Israel and Hamas agreed to a temporary cease-fire in January, the Yemeni militants suspended their campaign. But they vowed to resume attacks as truce talks faltered and Israel blocked humanitarian aid from entering the Gaza Strip this month.

Mr. Trump said on Saturday that he had ordered the military to launch “decisive and powerful” actions against the militia, which controls most of northern Yemen. He said the Houthis “have waged an unrelenting campaign of piracy, violence and terrorism” against American ships and other vessels, attacks he said were funded by Iran. The strikes, he added, were intended also as a warning to Iran.

Defense Secretary Pete Hegseth echoed the president’s statement, writing on social media Saturday that “Houthi attacks on American ships & aircraft (and our troops!) will not be tolerated; and Iran, their benefactor, is on notice.”

The Yemeni group, for its part, said Tuesday that it had targeted a U.S. aircraft carrier four times in the previous three days and had thwarted an air attack.

In a briefing with reporters on Monday, however, Lt. Gen. Alexus G. Grynkewich of the U.S. Air Force, who is also director for operations of the Joint Staff, dismissed the Houthis’ claims, saying, “They missed by a hundred miles.” He added that it was “hard to tell what they are doing, given their level of incompetence.”

“Initial estimates” showed dozens of Houthi casualties after the weekend strikes, General Grynkewich added, including to technical weapons experts, but he said there were no indications the American-led campaign had led to civilian casualties.

Anis al-Asbahi, a spokesman for the Houthi-run Health Ministry in Yemen, said on Sunday that the strikes had killed at least 53 people and wounded 98 others.

Sean Parnell, a spokesman for the Defense Department, said in the news briefing on Monday, “We will use overwhelming lethal force until we have achieved our objective.” But he said that it would not be an “endless offensive,” and that the “clear end state” would be when the Houthis stopped attacking commercial ships.

Mr. Parnell said that since 2023 the militant group had targeted American warships in regional waters 170 times, and commercial vessels 145 times. In November 2023, the rebels seized the MV Galaxy Leader, holding sailors from Bulgaria, Mexico, the Philippines, Romania and Ukraine for more than a year.

This past January, the rebel group released 25 of the ship’s crew members.

An international team of astronomers on Wednesday unveiled the most compelling evidence to date that dark energy — a mysterious phenomenon pushing our universe to expand ever faster — is not a constant force of nature but one that ebbs and flows through cosmic time.

Dark energy, the new measurement suggests, may not resign our universe to a fate of being ripped apart across every scale, from galaxy clusters down to atomic nuclei. Instead, its expansion could wane, eventually leaving the universe stable. Or the cosmos could even reverse course, eventually doomed to a collapse that astronomers refer to as the Big Crunch.

The latest results bolster a tantalizing hint from last April that something was awry with the standard model of cosmology, scientists’ best theory of the history and the structure of the universe. The measurements, from last year and this month, come from a collaboration running the Dark Energy Spectroscopic Instrument, or DESI, on a telescope at Kitt Peak National Observatory in Arizona.

“It’s a bit more than a hint now,” said Michael Levi, a cosmologist at Lawrence Berkeley National Laboratory and the director of DESI. “It puts us in conflict with other measurements,” Dr. Levi added. “Unless dark energy evolves — then, boy, all the ducks line up in a row.”

The announcement was made at a meeting of the American Physical Society in Anaheim, Calif., and accompanied by a set of papers describing the results, which are being submitted for peer review and publication in the journal Physical Review D.

“It’s fair to say that this result, taken at face value, appears to be the biggest hint we have about the nature of dark energy in the ~25 years since we discovered it,” Adam Riess, an astrophysicist at Johns Hopkins University and the Space Telescope Science Institute in Baltimore who was not involved in the work but shared the 2011 Nobel Prize in Physics for discovering dark energy, wrote in an email.

But even as the DESI observations challenged the standard model of cosmology, a separate result has reinforced it. On Tuesday, the multinational team that ran the Atacama Cosmology Telescope in Chile released the most detailed images ever taken of the infant universe, when it was a mere 380,000 years old. (That telescope was decommissioned in 2022.)

Their report, not yet peer-reviewed, seems to confirm that the standard model was operating as expected in the early universe. One element in that model, the Hubble constant, describes how fast the universe is expanding, but over the last half-century measurements of the constant have starkly disagreed, an inconsistency known as the Hubble tension. Theorists have mused that perhaps an additional spurt of dark energy in the very early universe, when conditions were too hot for atoms to form, could resolve this tension.

The latest Atacama results seem to rule out this idea. But they say nothing about whether the nature of dark energy might have evolved later in time.

Both reports evoked effusive praise from other cosmologists, who simultaneously confessed to a cosmic confusion about what it all meant.

“I don’t think much is left standing as far as good ideas for what might explain the Hubble tension at this point,” said Wendy Freedman, a cosmologist at the University of Chicago who has spent her life measuring the universe and was not involved in either study.

Michael Turner, a theorist at the University of Chicago, who was also not involved in the studies, said: “The good news is, no cracks in the cosmic egg. The bad news is, no cracks in the cosmic egg.”

Dr. Turner, who coined the term “dark energy,” added that if there was a crack, “it has not opened wide enough — yet — for us to clearly see the next big thing in cosmology.”

Astronomers often compare galaxies in an expanding universe to raisins in a baking cake. As the dough rises, the raisins are carried farther apart. The farther they are from each other, the faster they separate.

In 1998, two groups of astronomers measured the expansion of the universe by studying the brightness of a certain type of supernova, or exploding star. Such supernovas generate the same amount of light, so they appear predictably fainter at farther distances. If the expansion of the universe were slowing, as scientists believed at the time, light from faraway explosions should have appeared slightly brighter than foreseen.

To their surprise, the two groups found that the supernovas were fainter than expected. Instead of slowing down, the expansion of the universe was actually speeding up.

No energy known to physicists can drive an accelerating expansion; its strength should abate as it spreads ever more thinly across a ballooning universe. Unless that energy comes from space itself.

This dark energy bore all the earmarks of a fudge factor that Albert Einstein inserted into his theory of gravity back in 1917 to explain why the universe was not collapsing under its own weight. The fudge factor, known as the cosmological constant, represented a kind of cosmic repulsion that would balance gravity and stabilize the universe — or so he thought. In 1929, when it became clear that the universe was expanding, Einstein abandoned the cosmological constant, reportedly calling it his biggest blunder.

But it was too late. One feature of quantum theory devised in 1955 predicts that empty space is foaming with energy that would produce a repulsive force just like Einstein’s fudge factor. For the last quarter-century, this constant has been part of the standard model of cosmology. The model describes a universe born 13.8 billion years ago, in a colossal spark known as the Big Bang, and composed of 5 percent atomic matter, 25 percent dark matter and 70 percent dark energy. But the model fails to say what dark matter or dark energy actually are.

If dark energy really is Einstein’s constant, the standard model portends a bleak future: The universe will keep speeding up, forever, becoming darker and lonelier. Distant galaxies will eventually be too far away to see. All energy, life and thought will be sucked from the cosmos.

‘Something to go after’

Astronomers on the DESI team are trying to characterize dark energy by surveying galaxies in different eras of cosmic time. Tiny irregularities in the spread of matter across the primordial universe have influenced the distances between galaxies today — distances that have expanded, in a measurable way, along with the universe.

Data used for the latest DESI measurement consisted of a catalog of nearly 15 million galaxies and other celestial objects. Alone, the data set does not suggest that anything is awry with the theoretical understanding of dark energy. But combined with other strategies for measuring the expansion of the universe — for instance, studying exploding stars and the oldest light in the universe, emitted some hundred thousand years after the Big Bang — the data no longer lines up with what the standard model predicts.

The discrepancy between data and theory is at most 4.2 sigma (in the units of uncertainty preferred by physicists), representing one in 50,000 chances that the results are a fluke. But the mismatch is not yet at five sigma (equal to one in 3.5 million chances), the stringent standard set by physicists to claim a discovery.

Still, the disconnect is enticingly suggestive that something in the cosmological model is not well understood. Scientists might need to revise how they interpret gravity or make sense of the ancient light from the Big Bang. DESI astronomers think the problem could be the nature of dark energy.

“If we introduce a dynamical dark energy, then the pieces of the puzzle fit together better,” said Mustapha Ishak-Boushaki, a cosmologist at the University of Texas at Dallas who helped lead the latest DESI analysis.

Will Percival, a cosmologist at the University of Waterloo in Ontario and a spokesperson for the DESI collaboration, expressed excitement about what lies on the horizon. “This is actually a little bit of a shot in the arm for the field,” he said. “Now we’ve got something to go after.”

In the 1950s, astronomers claimed that only two numbers were needed to explain cosmology: one related to how fast the universe was expanding and another describing its deceleration, or how much that expansion was slowing down. Things changed in the 1960s, with the discovery that the universe was bathed in light from the Big Bang, known as the cosmic microwave background. Measuring this background radiation allowed scientists to investigate the physics of the early universe and the way that galaxies subsequently formed and evolved. As a result, the standard model of cosmology now requires six parameters, including the density of both ordinary and dark matter in the universe.

As cosmology has become more precise, additional tensions have arisen between predicted and measured values of these parameters, leading to a profusion of theoretical extensions to the standard model. But the latest results from the Atacama Cosmology Telescope — the clearest maps to date of the cosmic microwave background — seem to slam the door on many of these extensions.

DESI will continue collecting data for at least another year. Other telescopes, on the ground and in space, are charting their own views of the cosmos; among them are the Zwicky Transient Facility in San Diego, the European Euclid space telescope and NASA’s recently launched SPHEREx mission. In the future, the Vera C. Rubin Observatory will begin recording a motion picture of the night sky from Chile this summer, and NASA’s Roman Space Telescope is set to launch in 2027.

Each will soak up the light from the sky, measuring pieces of the cosmos from different perspectives and contributing to a broader understanding of the universe as a whole. All serve as ongoing reminders of just what a tough egg the universe is to crack.

“Each of these data sets comes with its own strengths,” said Alexie Leauthaud, a cosmologist at the University of California, Santa Cruz, and a spokesperson for the DESI collaboration. “The universe is complicated. And we’re trying to disentangle a lot of different things.”

Ukraine agreed to halt strikes on energy sites

President Volodymyr Zelensky of Ukraine agreed yesterday to Russia’s offer of a mutual pause in attacks on energy targets for 30 days as a step toward a broader cease-fire. He discussed the pause during a phone call with President Trump, who described the conversation as “very good.”

The two leaders spoke a day after Trump’s conversation with Vladimir Putin, Russia’s leader. It was the first time Trump and Zelensky had spoken since their disastrous Oval Office meeting last month.

Zelensky called the conversation “positive, very substantive and frank,” making clear that he had thanked Trump for America’s support.

Trump also floated the idea that the U.S. could take control of Ukrainian power plants — an idea that Ukrainian energy experts said was probably unworkable. Technical teams will meet in Saudi Arabia “in the coming days,” a White House statement said. They will discuss broadening the pause to cover activity in the Black Sea, “on the way to a full cease-fire.”

What’s next: Zelensky said that the agreement would need U.S. monitoring to work, and that Kyiv would prepare a list of sites that needed protection. “Just the assertion and the word of Putin that he will not strike energy sites is too little,” he said. “War has made us practical people.”

Analysis: Most of what Putin agreed to on Tuesday’s call with Trump was spun as a concession, but the Russian leader didn’t really give any ground.

More on Trump

An agreement would allow the country to help build European fighter jets and other equipment at its own industrial facilities.

The goal is to strengthen the E.U. defense industry and offer Canada a credible alternative to the U.S., according to officials with direct knowledge of the talks. Canada’s new leader, Prime Minister Mark Carney, this week made Paris and London the destinations of his first overseas trip since taking office on Friday, calling Canada “the most European of non-European countries.”

Background: Canada has been a regular U.S. contractor, and its factories produce munitions, tanks, aircraft, technological defense systems and navy ships. A 2022 review found that the top destination of its military equipment, by far, was the U.S.

What’s next: The initiative and partnership will take years to bear fruit. E.U. defense has been falling behind because of U.S. dominance and underinvestment, a dire situation that has become more apparent after the drive to arm Ukraine depleted the arsenals of E.U. members.

Israel seized part of a central corridor in Gaza

Yesterday, Israeli forces took over parts of a major corridor that divides Gaza, in the most significant ground operation since the collapse of a cease-fire with Hamas.

The military said soldiers had begun “targeted ground activities” along the road, known as the Netzarim Corridor, to create a “partial buffer zone” in the territory between the north and south.

Context: Israel has not returned to a full-scale war in Gaza, but, by stepping up attacks, Israeli leaders appeared to be trying to force Hamas to agree to more favorable terms for a settlement.

In Jerusalem, thousands of Israeli protesters called for a renewed cease-fire.

Photos from the Gaza strikes: A cease-fire spared Palestinians the task of identifying bodies. Our photographers captured this grim return to the past.

In Paraswara, a village in a rural corner of India, 12 men were sworn in this month to form a local government. A video of the ceremony went viral and caused a scandal because half of those men hadn’t been elected — their wives had.

The sidelining of women in rural Indian politics is nothing new, but some are starting to push back against “boss husbands.”

Lives lived: Anthony Dolan, who as Ronald Reagan’s chief speechwriter deployed the phrase “evil empire” in 1983 to describe the Soviet Union, died at 76.

A gorgeous digital window into feudal Japan

Open-world video games tend to have a central story, augmented with mostly extraneous side quests and hidden areas. Assassin’s Creed Shadows, which takes place in 16th-century Japan, reverses the formula. Here, the story takes a back seat to historical renderings that are as accurate as you’ll find without airfare.

As players step into the shoes of an African-born samurai and a young ninja on a tour of vengeance, the plot is outshone by the game’s fascinating picture of this vibrant era. The game comes out today in most countries. Read our review.

In a propaganda video released by the government of El Salvador, shackled detainees are forcefully led off planes as drones film overhead.

The music builds and the men are pushed into armored vehicles and taken to a large prison.

Their heads are shaved and they are moved in organized lines into large cells — all while the camera rolls.

The video features Venezuelan migrants recently deported from the United States, whom U.S. officials accuse of being gang members, according to Salvadoran officials. The clip also shows suspected members of the MS-13 gang, they said. The deportation flights landed in El Salvador despite a federal judge ordering that the planes reverse course and return the detainees to the United States.

The three-minute clip, released on Sunday morning by El Salvador’s president, was viewed almost 39 million times in three days across social media, and was repeatedly played on cable news.

While the United States didn’t release the video, it is an extraordinary depiction of detained migrants subject to American deportation proceedings, which are rarely so openly broadcast.

But the style of video is not new in El Salvador.

President Nayib Bukele, a former publicist who was elected the country’s leader in 2019, has made prosecuting and incarcerating El Salvador’s gangs a key part of his tenure.

He has highlighted his hard-line approach against longstanding gang violence with polished videos of arrests and imprisonments, like this heavily produced video from 2023 showing detainees being moved into a new prison facility.

“These are videos that typically humiliate and try to dehumanize the people who are detained there, and in this case deported,” said Juanita Goebertus Estrada, the director of the Americas division of Human Rights Watch.

The Trump administration has disclosed little about the men, including any evidence that they are gang members. It says videos like this show how President Trump is making good on his promises to stop illegal immigration and conduct mass deportations.

Last month, Secretary of State Marco Rubio visited El Salvador. He announced that the country’s president had offered to take in deportees of any nationality, including U.S. citizens, and house them for a fee at a new megaprison called the Terrorism Confinement Center, or CECOT, a hulking site that can house up to 40,000 inmates.

Opened in 2023 to detain people accused of being gang members, the facility was introduced with highly produced videos by Mr. Bukele’s team, showcasing the transfer of detainees.

“It’s the shock value,” Ricardo Valencia, a press officer at the Salvadoran Embassy in Washington from 2010 and 2014, and a public relations professor at California State University, Fullerton, said of the videos. “But this tells you about how little rule of law there is in El Salvador. The cruelty is the point.”

Over the weekend, the Trump administration said that El Salvador would receive $6 million for taking in hundreds of deportees, most of whom the U.S. government said were members of the Venezuelan criminal group Tren de Aragua, without offering evidence or the detainees’ names. Officials said the deal also included the transfer of about two dozen suspected members of MS-13 who were being held in the United States awaiting charges.

Normally, official U.S. depictions of deportations or detention centers are more circumspect, not showing migrants’ faces, if there is video at all.

But under Mr. Trump, who campaigned on a hard-line anti-immigration stance and the promise of mass deportations, U.S. officials have presented a new, more visceral propaganda campaign.

Mr. Rubio and Elon Musk shared Mr. Bukele’s video online. Mr. Trump thanked him, saying, “We will not forget!”

In recent weeks, the White House has released videos celebrating their deportation efforts.

The White House also released photos styled as Old West “wanted” posters, featuring men “ARRESTED” by immigration officials, who they say have been accused of crimes like rape, murder and kidnapping.

These images, stamped with a White House logo, were promoted to demonstrate what the White House says is a determination to follow the nation’s immigration laws. But they also served to publicly shame immigrants, some of whom had not been convicted.

On Monday, the White House posted a clip on X of a shackled migrant being searched set to Semisonic’s 1998 rock hit “Closing Time.”

The White House press secretary, Karoline Leavitt, said the video was meant to encourage “illegal immigrants to actively self-deport, to maybe to save themselves from being in one of these fun videos.”

These types of videos first became common in El Salvador in 2022, after a surge in gang violence in the Central American country led the government to impose a state of emergency — one that remains in place three years later. The military and the police began a campaign of mass arrests, with many people imprisoned without due process.

Although the crackdown significantly reduced gang violence, it simultaneously eroded civil liberties and centralized power under Mr. Bukele.

Human rights groups raised alarms about the lack of due process for tens of thousands of detainees (some people with no gang ties were ensnared), and the conditions in which they were held. More than 300 people have died in government custody in the last three years, according to Human Rights Watch.

When Mr. Bukele’s administration opened the new detention facility in 2023, it posted a 30-minute guided tour. Since then they have brought international media and social media influencers in for tours that have garnered huge view counts on YouTube.

Mr. Bukele’s new partnership with the United States is likely to further embolden his government’s production of such propaganda videos.

“We continue advancing in the fight against organized crime,” Mr. Bukele wrote alongside the video over the weekend. “But this time, we are also helping our allies.”

Axel Boada contributed video production.