Here is a closer look at why the administration says it is instituting full bans on foreign nationals traveling to the U.S. from 12 nations.

Trump framed the new restrictions, which primarily target African and Asian countries, as necessary to fortify national security and combat terrorism.

The travel ban results from a Jan. 20 executive order Trump issued requiring the departments of State and Homeland Security and the director of national intelligence to compile a report on “hostile attitudes” toward the U.S. and whether entry from certain countries represented a national security risk.