In this March 15, 2019, photo, families hoping to seek asylum in the United States wait on the bridge connecting Reynosa, Mexico, to Hidalgo, Texas.
In this March 15, 2019, photo, families hoping to seek asylum in the United States wait on the bridge connecting Reynosa, Mexico, to Hidalgo, Texas.

A U.S. judge on Monday issued an injunction halting the Trump administration's policy of sending some asylum-seekers back across the southern border to wait out their cases in Mexico.

The ruling is slated to take effect on Friday, according to the order by U.S. District Judge Richard Seeborg in San Francisco. The injunction will apply nationwide.

The ruling removes at least temporarily a controversial Trump administration strategy aimed at slowing a flood of immigrants, mostly from Central America, that swelled last month to the highest level in a decade.

FILE - In this March 14, 2019, photo, Jose Fermin
FILE - Jose Fermin Gonzalez Cruz holds his son, William Josue Gonzales Garcia, 2, as they wait with other families who crossed the border near McAllen, Texas, for Border Patrol agents to check names and documents, March 14, 2019.

Because of limits on how long children are legally allowed to be held in detention, many of the families are released to await U.S. immigration court hearings, a process that can take years because of ballooning backlogs. In response, the Trump administration in January started sending some migrants to wait out their U.S. court dates in Mexican border cities.

The Department of Homeland Security said last week that it planned to expand the program.

A U.S. Department of Justice spokesman did not immediately respond to a request for comment.