"I have just ordered Homeland Security to step up our already Extreme Vetting Program. Being politically correct is fine, but not for this!" Trump tweeted.
Last week, global airlines began implementing security interviews for US-bound travelers before checking in for flights.
The president's attempts at banning travelers from several mainly Muslim nations have been met with successive legal challenges.
His administration has announced that it would resume accepting refugees after a 120-day ban, though arrivals from 11 "high-risk" countries, most of them home to Muslim majorities, will still be blocked. DM