Kilmar Abrego Garcia, whose mistaken deportation to El Salvador became a political flashpoint in the Trump administration's stepped-up immigration enforcement, was returned to the United States on Friday to face criminal charges related to what the Trump administration said was a large human smuggling operation that brought immigrants into the country illegally.

His abrupt release from El Salvador closes one chapter and opens another in a saga that yielded a remarkable, months-long standoff between Trump officials and the courts over a deportation that officials initially acknowledged was done in error but then continued to stand behind in apparent defiance of orders by judges to facilitate his return to the U.S.

The development occurred after U.S. officials presented El Salvador President Nayib Bukele with an arrest warrant for federal charges in Tennessee accusing Abrego Garcia of playing a key role in smuggling immigrants into the country for money.

He is expected to be prosecuted in the U.S. and, if convicted, will be returned to his home country of El Salvador at the conclusion of the case, officials said Friday.

Abrego Garcia's attorneys called the case “baseless."

Democrats and immigrant rights group had pressed for Abrego Garcia’s release, with several lawmakers — including Sen. Chris Van Hollen of Maryland, where Abrego Garcia had lived for years — even traveling to El Salvador to visit him.

A federal judge had ordered him to be returned in April and the Supreme Court rejected an emergency appeal by directing the government to work to bring him back.

But the news that Abrego Garcia, who had an immigration court order preventing his deportation to his native country over fears he would face persecution from local gangs, was being brought back for the purpose of prosecution was greeted with dismay by his lawyers.

“What happened today is an abuse of power,” his attorney Simon Sandoval-Moshenberg said.

He said he plans to meet with him soon and will “vigorously defend” him against the new charges.

“This administration … instead of simply admitting their mistake, they’ll stop at nothing at all, including some of the most preposterous charges imageable, just to avoid admitting they made a mistake, which is what everyone knows happened in this case,” he said.