Elected last year on a promise to crack down on migrants, Trump invoked the 1798 Alien Enemies Act in an attempt to swiftly deport accused members of Tren de Aragua, a criminal gang originating from Venezuelan prisons that his administration labels a terrorist group.

High court acted in an emergency appeal from the American Civil Liberties Union contending that immigration authorities appeared to be moving to restart removals under the Alien Enemies Act of 1798.

The Supreme Court blocked the Trump administration from deporting a second wave of Venezuelan immigrants under the Alien Enemies Act after lawyers rushed to the court and alleged that the administration was about to send dozens or hundreds of detainees to El Salvador in defiance of an earlier ruling by the justices.