WASHINGTON—The Trump administration is planning to invoke a sweeping wartime authority known as the Alien Enemies Act in an effort to speed up deportations, according to an official familiar with the discussions.

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.

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.

President Trump is expected to invoke an 18th century law giving him wartime powers to deport migrants en masse. He intends to apply the Alien Enemies Act of 1798 as soon as Friday, multiple sources have confirmed to CNN.