El Salvador's President Nayib Bukele, sitting next to President Donald Trump in the Oval Office, said on Monday he will not return Kilmar Abrego García, a migrant from Maryland who was wrongfully deported.

"I don't have the power to return him to the United States," Bukele said when a reporter asked.

"How could I smuggle a terrorist into the United States?" he added, repeating the Trump administration's claim that Abrego García is a "terrorist" gang member of MS-13 -- which it has not claimed in the court battle over his fate.

Bukele, the self-described "world's coolest dictator" who has become a key partner in Trump's controversial deportations, called it a "preposterous question," saying "of course, I'm not going to do it," as Trump nodded in agreement.

Abrego Garcia's family and lawyer have denied he has any affiliation with the MS-13 gang. The administration has not publicly presented evidence that Abrego Garcia is a member of MS-13 or a terrorist, and he has not been charged with any crime or convicted.

Abrego Garcia was sent to El Salvador's infamous CECOT prison following what the government said was an "administrative error," despite a 2019 court order barring his deportation to El Salvador. His attorneys say he escaped El Salvador in 2011 due to political violence.

Benjamin Osorio, an attorney for Abrego Garcia, told ABC News that he has "very serious concerns" in response to Salvadoran President Bukele's remarks that he doesn't "have the power" to return the Maryland man to the U.S.

Osorio said that Bukele and President Trump are "both incentivized" not to bring Abrego Garcia back.

"Bukele's doing this because that's obviously what Trump wants, right?," Osorio said. "Because if they bring [Abrego Garcia] back, it's going to be a media frenzy, and this guy's gonna be all over the news, and then we'll know about his experience."

The Supreme Court last week ordered the Trump administration to "facilitate" the return of Abrego Garcia. Trump on Friday said, "If the Supreme Court said bring somebody back, I would tell them to do that. I respect the Supreme Court."

But Trump changed course a day later, instead suggesting the fate of those deported rested with Bukele.

And on Monday, Trump ignored a question on his statement that he would abide by the Supreme Court ruling, instead attacking the CNN reporter who asked about it.

His top officials repeated his claim that what happens next is solely up to El Salvador and that courts can't direct how the executive branch engages in foreign relations.

"It's up to El Salvador if they want to return him," Attorney General Pam Bondi said.

"I don't understand what the confusion is," said Secretary of State Marco Rubio. "This individual is a citizen of El Salvador. He was illegally in the United States and was returned to his country."