The Trump administration made a last-ditch appeal Monday to the Supreme Court hoping to overturn a US federal judge's order to repatriate a Salvadoran migrant who was mistakenly deported last month.

Kilmar Abrego Garcia, 29, who was living in the eastern state of Maryland, was among more than 200 people sent to a notorious prison in El Salvador under President Donald Trump's crackdown on undocumented migrants.

US District Judge Paula Xinis ordered Friday that Abrego Garcia be returned to the United States by 11:59 pm on Monday after Justice Department lawyers admitted he was deported due to an "administrative error."

A federal appeals court upheld the decision, with Judge Harvie Wilkinson writing: "There is no question that the government screwed up here."

The Trump administration on Monday took its case to the conservative-dominated Supreme Court, labeling the repatriation order "unprecedented and indefensible."

In a filing to the high court, it slammed the ruling as a "demand that the United States let a member of a foreign terrorist organization into America tonight."

The White House has insisted that Abrego Garcia, who is married to a US citizen, is a member of the Salvadoran gang MS-13 -- though Judge Xinis dismissed this claim as lacking evidence.

Abrego Garcia had been living in the United States under protected legal status since 2019, when a judge ruled he should not be deported because he could be harmed in El Salvador.

The Trump administration conceded again in its Supreme Court application that Abrego Garcia's deportation to El Salvador was an error, but added he could still be removed "anywhere else in the world."

Three planeloads of undocumented migrants were flown from the United States to El Salvador on 15 March.

The Trump administration alleged that most of the deportees were part of the Venezuelan gang Tren de Aragua, but some attorneys have said that their clients were not members, had committed no crimes and were targeted largely because of their tattoos.