DHS is telling some migrants who entered the U.S. using the CBP One app to leave immediately, part of a broader push to revoke temporary legal protections known as humanitarian parole.

The lawsuit alleges Trump's actions go against protections provided by Congress and backed by the courts.

Immigration officials now have permission to quickly expel migrants temporarily admitted via the CBP One App and a separate program for certain people fleeing Cuba, Haiti, Nicaragua and Venezuela.

Lee Gelernt with the ACLU said the action goes "way beyond anything that even President Trump has tried in the past."

The policy, which was created and implemented during the first Trump administration in 2019, resulted in tens of thousands of migrants waiting for extended periods in Mexico.

Incoming president Donald Trump has vowed to end the CBP One app, which people outside the U.S. use to book appointments to petition for asylum.

U.S. District Judge Jon Tigar blocked a similar policy during the Trump administration, and immigrant advocates had urged him to do the same in this case.

Biden administration rules have one main legal pathway to seek asylum for migrants already at the border: a mobile app called CBP One. Immigrant advocates and immigration hardliners have objections.

Immigration authorities touted a major update meant to improve CBP One, an app that's now the main authorized portal to seek asylum at the border. But migrants in Juárez say it's still not working.