A US federal appeals court allowed the Trump administration on Monday to temporarily resume summarily deporting undocumented migrants to countries that are not their own.

The US Court of Appeals for the First Circuit, in a 2-1 vote, lifted a block on the so-called "third-country" deportations that had been imposed by a lower court.

District Judge Brian Murphy ruled last month that third-country deportations were unlawful but put his ruling on hold to allow the government time to file an appeal.

The appeals court lifted the stay put on the deportations by the district court judge and said they may continue while the case is litigated.

Attorney General Pam Bondi welcomed the appeals court ruling calling it a "key win" for President Donald Trump's immigration agenda.

Trump campaigned for the White House on a pledge to deport millions of undocumented migrants.

In his ruling, Murphy had noted that Congress has made it US policy not to deport people to countries where their lives would be in danger or they could be subject to torture.

Murphy, an appointee of Democratic president Joe Biden, had previously sought to block the deportation of a group of migrants to war-torn South Sudan but was overruled by the conservative-dominated Supreme Court.

According to the US authorities, the eight men -- two from Myanmar, two from Cuba, and one each from Vietnam, Laos, Mexico and South Sudan -- were convicted violent criminals.

The Trump administration has defended third-country deportations as necessary since the home nations of some of those who are targeted for removal sometimes refuse to accept them.