A US judge has 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 US District Judge Richard Seeborg in San Francisco, and 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.
Because of limits on how long children are legally allowed to be held in detention, many of the families are released to await US immigration court hearings, a process that can take years because of backlogs.
In response, the Trump administration in January started sending some migrants to wait out their US court dates in Mexican border cities under a policy known as Migrant Protection Protocols, or MPP.
The Department of Homeland Security said last week that it planned to expand the program.
A US Department of Justice spokesman declined to comment. The White House did not immediately respond to a request for comment.
Seeborg said his ruling turned on the narrow question of whether the Trump administration had followed administrative law in implementing the policy.
"The legal question is not whether the MPP is a wise, intelligent, or humane policy, or whether it is the best approach for addressing the circumstances the executive branch contends constitute a crisis," wrote Seeborg.
The judge said the government shall permit the 11 plaintiffs in the case to enter the United States beginning on Sunday. He said the government still retained the right to detain the asylum-seekers pending the outcome of their case.
The plaintiffs include legal service organisations and migrants who fled Guatemala, Honduras and El Salvador to escape what they said was extreme violence, rape and death threats.
Apprehensions by border agents were on track to top 100,000 in March, the highest level in a decade, according to the US Customs and Border Protection.
