The Department of Homeland Security (DHS) is terminating parole protections for people who entered the country through the CBP One app, revoking legal status for nearly a million migrants who came to the U.S. during the Biden administration.

Roughly 985,000 people used the app to make appointments at a port of entry at the border, with those who entered often permitted to seek asylum and given temporary work authorization.

“The Biden Administration abused the parole authority to allow millions of illegal aliens into the U.S. which further fueled the worst border crisis in U.S. history. Under federal law, Secretary [Kristi] Noem — in support of the President — has full authority to revoke parole. Canceling these paroles is a promise kept to the American people to secure our borders and protect national security,” the DHS said in a statement.

The administration has begun sending email notices to affected migrants telling them to self-deport through the Trump administration’s version of the app, now called CBP Home.