The Trump administration says the group should be treated as an invading force. Critics say it’s a pretext for the administration’s anti-immigrant narrative.

Trump labeled the Tren de Aragua an invading force when he invoked the Alien Enemies Act, a 1798 authority that allows the president to deport any noncitizen during wartime.

President Trump invoked the Alien Enemies Act of 1798 against Tren de Aragua members, provoking a legal fight. Here's what to know about the controversial law, which was last used during World War II.