'Homegrowns are next': Trump doubles down on sending American 'criminals' to foreign prisons

President Donald Trump on Monday doubled down on his idea of sending U.S. citizens to foreign prisons, telling El Salvador's President Nayib Bukele he wanted to send "homegrown criminals" to his country next, according to a video posted by Bukele's office on X.

The comments came as Trump welcomed Bukele, a key partner in his migrant deportations, to the White House amid controversy over the Supreme Court saying the administration should "facilitate" the return of a migrant from Maryland wrongfully sent to a notorious Salvadoran mega-prison.

As the two men entered the Oval Office, before reporters were allowed in the room, Trump discussed his proposal to send what he called American "criminals" accused of violent crimes to El Salvador and told Bukele he needed to build more prisons to house them.

"Homegrown criminals next," Trump said, according to a livestream posted by Bukele's office. "I said homegrowns are next, the homegrowns. You gotta build about five more places."

Bukele was heard responding "alright" and others in the room laughed.

"It's not big enough," Trump added.

Trump and various White House officials have repeatedly floated the idea of sending U.S. citizens to El Salvador and other places -- something legal experts have said would be flatly unconstitutional.

On Monday, during a spray with reporters, Trump said his team was "studying" the issue.

"If it's a homegrown criminal, I have no problem," Trump said. "Now we're studying the laws right now, Pam [Bondi] is studying. If we can do that, that's good."

"And I'm talking about violent people. I'm talking about really bad people. Really bad people. Every bit as bad as the ones coming in," he continued.

Bukele first offered to house violent U.S. criminals shortly after Trump was inaugurated.

When Secretary of State Marco Rubio announced the proposal from Bukele back in early February, he called the it "an act of extraordinary friendship." Though at the time, Rubio also noted there would be constitutional questions about such a move, saying there are "obviously legalities involved."

Bukele on Monday said he was "very eager to help" the Trump administration.

"In fact, Mr. President, you have 350 million people to liberate. You know, but to liberate 350 million people, you have to imprison some," Bukele said.

ABC News' Alexandra Hutzler contributed to this report.