“When they paused the program and didn’t allow any new people enrolled in it but officially the program was in place until today, until a few hours ago,” Austin Kocher, a lead researcher with Transactional Records Access Clearinghouse, a nonprofit from Syracuse University, that tracks U.S. immigration cases.

After he took office, Biden’s administration began to convert MPP cases and about 10,000 of the asylum-seekers placed in MPP have been legally allowed to enter the United States while they await their immigration hearings and proceedings, Kocher said. But 25,000 to 30,000 cases still remain, with many migrants waiting in dangerous border cities like Ciudad Juarez, across from El Paso, Texas, and Reynosa, Mexico, across from McAllen, Texas.

“The program essentially meant that any asylum-seekers who arrived at the U.S.-Mexico border would not be processed through normal channels but would be forced to remain in Mexico where many faced conditions of violence and kidnapping,” Kocher said.

More than 42,000 asylum-seekers who were placed in MPP had their cases resolved under Donald Trump’s presidency, an overwhelming majority of whom were not allowed into the United States during the Trump administration.

“These are individuals most of whom never really got a full asylum hearing at all and may have returned to dangerous situations or conditions,” Kocher said. His organization tracks cases by Freedom of Information requests.