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.

President Donald Trump is planning sweeping new executive actions designed to crack down on illegal border crossings and target undocumented migrants already in the US.

CBP One, a border app that has allowed nearly 1 million people to legally enter the United States with eligibility to work, was abruptly shut down on Monday, shortly after President-elect Donald Trump took office.

The CBP One app rolled out by President Biden — which allowed migrants to request asylum by posting personal information and scheduling appointments at eight ports of entry into the United States — is no longer available.