The United States Department of Homeland Security said that it will revoke legal protections for hundreds of thousands of Cubans, Haitians, Nicaraguans and Venezuelans, setting them up for potential deportation in about a month.

The order applies to about 532,000 people from the four countries who came to the United States since October 2022.

They arrived with financial sponsors and were given two-year permits to live and work in the US Homeland Security Secretary Kristi Noem said they will lose their legal status on April 24, or 30 days after the publication of the notice in the Federal Register.

The new policy impacts people who are already in the U.S. and who came under the humanitarian parole program. It follows an earlier Trump administration decision to end what it called the “broad abuse” of the humanitarian parole, a long-standing legal tool presidents have used to allow people from countries where there’s war or political instability to enter and temporarily live in the US.

During his campaign President Donald Trump promised to deport millions of people who are in the U.S. illegally, and as president he has been also ending legal pathways for immigrants to come to the U.S. and to stay.

DHS said parolees without a lawful basis to stay in the U.S. “must depart” before their parole termination date.

“Parole is inherently temporary, and parole alone is not an underlying basis for obtaining any immigration status,” DHS said.

Before the new order, the beneficiaries of the program could stay in the U.S. until their parole expires, although the administration had stopped processing their applications for asylum, visas and other requests that might allow them to remain longer.

The administration decision has already been challenged in federal courts.

A group of American citizens and immigrants sued the Trump administration for ending humanitarian parole and are seeking to reinstate the programs for the four nationalities.

Lawyers and activists raised their voices to denounce the government’s decision.

Friday’s action is “going to cause needless chaos and heartbreak for families and communities across the country,” said Karen Tumlin, founder and director of Justice Action Center, one of the organizations that filed the lawsuit at the end of February. She called it “reckless, cruel and counterproductive.”

The Biden administration allowed up to 30,000 people a month from the four countries to come to the United States for two years with eligibility to work. It persuaded Mexico to take back the same number from those countries because the US could deport few, if any, to their homes.

Cuba generally accepted about one deportation flight a month, while Venezuela and Nicaragua refused to take any. All three are US adversaries.

Haiti accepted many deportation flights, especially after a surge of migrants from the Caribbean country in the small border town of Del Rio, Texas, in 2021. But Haiti has been in constant turmoil, hampering U.S. efforts.

Since late 2022, more than half a million people have come to the U.S. under the policy, also known as CHNV. It was a part of the Biden administration’s approach to encourage people to come through new legal channels while cracking down on those who crossed the border illegally.