PRESIDENT Donald Trump on Monday hosted El Salvador's President Nayib Bukele, the self-described "world's coolest dictator" who is now the US leader's key ally in a controversial push to deport illegal migrants to a notorious Salvadoran prison.

The meeting comes as the White House faces pressure over the case of a father who was mistakenly deported to a jail in the Central American country - whose return a US court has ordered the Trump administration to facilitate.

As Trump welcomed Bukele outside the West Wing, the US president didn't answer when asked if he would request the return of the man, Kilmar Abrego Garcia.

Bukele, known for his stylish dress sense and social media savvy, is broadly popular at home for clamping down on once rampant drug gangs that terrorized El Salvador.

But the 43-year-old Salvadoran leader is accused of overseeing mass human rights violations, epitomised by a huge, brutal prison known as CECOT.

Shortly after Trump's inauguration for a second term, Bukele made the extraordinary offer to take in prisoners from the United States.

Trump took the Salvadoran leader up on his proposal, sending more than 250 migrants there after invoking a rarely used wartime law dating to 1798, which stripped the deportees of due process.

Slickly produced footage of their arrival -- including chained and tattooed men having their heads shaved and being frog-marched by masked guards -- was widely promoted by both the Salvadoran and US governments.

The Trump administration contends that the migrants are members of criminal gangs designated by the United States as terrorist organizations, including El Salvador's MS-13 and Venezuela's Tren de Aragua.

However, relatives of several of the men contend they have no connection to organised crime and, in some cases, had been swept up simply because they had tattoos unrelated to any gang activity.

'Administrative error'

The expulsion to El Salvador of Abrego Garcia has set off a major legal crisis, after the Trump administration admitted he had been deported in an "administrative error."

A federal judge ordered the government to "facilitate" Abrego Garcia's return to the United States, but Trump officials contend he is now solely in Salvadoran custody, leaving the man in legal limbo.

Trump's deputy chief of staff and migration hardliner Stephen Miller brushed off the court order on Monday, telling reporters: "We're going to continue to send foreign terrorist aliens to El Salvador as well as to many other countries."

Trump wrote on social media on Saturday that "our nations are working closely together to eradicate terrorist organizations and build a future of Prosperity."

US Secretary of State Marco Rubio said Sunday that 10 further "criminals" had arrived in El Salvador.

Aside from political benefits for both leaders, Bukele says El Salvador has so far been paid $6 million for taking deportees.

Despite the partnership, El Salvador was among the dozens of US trade partners that the Trump administration slapped with 10 percent tariffs.

The United States is the main destination for Salvadoran exports. Of the nearly $6.5 billion in goods exported from El Salvador in 2024, $2.1 billion went to the United States, including clothing, sugar and coffee, according to the central bank.

But Trump and Bukele also share a taste for strongman-style politics.

Since coming to power in 2019, Bukele has subdued his once gang-plagued nation of about six million people, sending his approval ratings soaring.

Trump's immigration policies, focused on what he says is the threat of a gang-led crime wave in the United States, are meanwhile among his most popular, receiving much higher ratings than on the economy.

Bukele sarcastically responded, "Oopsie... too late" when the first flights of deportees from the United States arrived in March despite a federal judge ordering a halt.

- AFP