Trump ended use of a border app to allow migrants to enter the country on two-year permits with eligibility to work, canceling tens of thousands of appointments into early February for people stranded in Mexico. Nearly 1 million people entered the U.S. at land crossings with Mexico by using the CBP One app.

President Trump began his immigration crackdown with a flurry of executive orders. Immigration experts say they lay out how he hopes to transform enforcement at the southern U.S. border and beyond.