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.

In more than 21 actions, Trump has moved to overhaul parts of the US immigration system, including how migrants are processed and deported from the US. The White House has since publicised some of these efforts.

If the Trump administration succeeds in deporting millions of immigrants, it will slow economic growth and productivity gains.