US President Joe Biden has come under fire for restoring a Trump-era policy that requires asylum seekers to wait in Mexico while their claims are processed.
Migrant groups said reinstating the Remain in Mexico programme would spur crime and violence in border camps.
Mr Biden had suspended the policy, calling it “inhumane”, but was ordered by courts to resume it.
The US and Mexican governments confirmed they would revive it.
Mr Biden’s administration has kept up one other major Trump-era border policy: Title 42, which allows for the quick expulsion of migrants on public health grounds.
Why is Remain in Mexico back?
Former US President Donald Trump introduced the programme, then known as the Migrant Protection Protocols, to send more than 60,000 asylum applicants back to Mexico.
Migrants were often left waiting in Mexico for months, where they sometimes fell prey to criminal gangs.
According to charity Human Rights First, there have been more than 1,500 publicly reported cases of kidnapping, rape, torture and other abuses against migrants returned to Mexico.
Mr Biden suspended the programme almost immediately after taking office, as part of a campaign pledge to reverse hardline immigration policies enacted by his
In June, Homeland Security Secretary Alejandro Mayorkas terminated the policy.
But in August a federal court Judge Matthew Kacsmaryk, a Trump appointee, ruled that the policy had been improperly cancelled.
The Biden administration is appealing against the decision.
White House Press Secretary Jen Psaki said on Thursday that the president stands by past remarks about the “unjustified human costs” of the programme.
“But we also believe in following the law,” she said.
The policy has been revamped to address Mexico’s concerns, including to limit time spent for each asylum application to six months.
Implementation is expected to begin next week at ports of entry in Texas and California.
Bbc.com