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

President Donald Trump has implemented sweeping uses of executive authority since returning to office in January. As he continues his crackdown on unauthorized immigration, the president is now reportedly looking to use a little-known law from the early days on the United States,

Experts predict a swift legal challenge to Trump's 'novel' approach of invoking wartime powers to target immigration.