Trump orders one million people to leave the US immediately

Hefty fines will also be issued to those failing to leave

The decision will affect more than 900,000 people who were allowed in the country using the CBP One app since January 2023.

They were generally allowed to remain in the United States for two years with authorization to work under a presidential authority called parole.

The Department of Homeland Security said: "Cancelling these paroles is a promise kept to the American people to secure our borders and protect national security."

Authorities confirmed termination notices were sent to CBP One beneficiaries but did not say how many. 

They were urged to voluntary self-deport using the same app they entered on, which has been renamed CBP Home.

The Department of Homeland Security has also announced that those who are in the U.S. illegally and refuse to leave will be charged $998 per day until they go.

A spokesperson said: "If they don't [leave], they will face the consequences. This includes a fine of $998 per day for every day that the illegal alien overstayed their final deportation order."

Officials are planning to roll out the fines under a rarely used 1996 law that allows fines to be imposed on those avoiding removal orders. 

The law was first enforced in 2018 under the Republican's first term.

Joe Biden's administration suspended the rule in 2021 claiming the penalties were 'ineffective and unnecessary punitive measures'.

One senior Trump administration official said the fines will be retroactive up to five years, dating back to 2019, which could result in penalties totalling over $1 million in some circumstances. 

In a letter sent to a Honduran family that entered the country at the end of last year, the Department of Homeland Security said: "It's time for you to abandon the United States."

Al Otro Lado, a nonprofit organization that provides legal aid to migrants, said some who received the revocation letters are from Honduras, El Salvador and Mexico.

The app was a crucial part of Biden's administration strategy as they attempted to discourage illegal border crossings.

By the end of December, 936,500 people had been allowed to enter with CBP One appointments at border crossings with Mexico. 

President Donald Trump ended CBP One for new entrants on his first day in office, stranding thousands in Mexico who had appointments into early February.

Homeland Security claim that Biden's use of parole authority — more than any president since it was created in 1952 — 'further fuelled the worst border crisis in U.S. history.'

The fines will only affect the 1.6 million migrants in the U.S. facing deportation orders.

Failure to provide the money will lead to the administration seizing the property of those individuals.