The Venezuelans, labeled terrorists and violent criminals by Trump, had been deported to the notorious CECOT prison, setting off a legal battle over executive power.

The Venezuelans being repatriated had originally been deported by the US under the Trump administration to El Salvador earlier this year, under the 1798 Alien Enemies Act, which gives a US president power to detain and deport natives or citizens of "enemy" nations without usual processes.

The Trump administration completed a large-scale prisoner swap with Venezuela on Friday, sending about 250 Venezuelans who had been deported and imprisoned in El Salvador back to their home country in exchange for 10 US nationals,