In the lead-up to the presidential election, Trump said he would carry out the “largest deportation program” in U.S. history—though efforts appear to have slowed down.

The act is a wartime authority that allows the president to detain and deport non-U.S. citizens from enemy countries.

Trump is expected to invoke the Alien Enemies Act as part of the efforts to carry out mass deportations, according to two U.S. officials familiar with the matter.