Hours earlier, thousands of would-be migrants had their immigration appointments cancelled after the new administration scrapped CBP One, an app used to book appearances at ports of entry at the border. In his inaugural address, Trump vowed that "all illegal entry will be halted" and that millions of "criminal aliens" will be deported.

President Trump is planning to invoke muscular presidential powers to begin a sweeping crackdown on immigration.

WASHINGTON - Newly sworn-in U.S. President Donald Trump said on Monday that he would declare illegal immigration a national emergency, send troops to the U.S.-Mexico border, and reinstate his "remain in Mexico" policy as part of a sweeping immigration crackdown.