The US Supreme Court on Friday allowed President Joe Biden's administration to end a Trump-era migrant programme that sent people looking to apply for asylum in the US back to Mexico while their cases were reviewed.
In a 5-4 ruling, the US high court held that Mr Biden's administration's decision to end the policy did not violate federal immigration law. The White House had argued that many of the applicants could be released into the US while they await their hearings.
Under the Migrant Protection Protocols, or the “Remain in Mexico” policy, federal officials sent asylum seekers back to Mexico where they remained while their cases were reviewed.
The process could take months or even years.
Chief Justice John Roberts and Justice Brett Kavanaugh joined the court's three liberal justices in the majority.
Friday's ruling fulfils a campaign promise made by Mr Biden, whose administration twice tried to end the policy. Last year the Supreme Court forced his administration to restart the programme, which required the White House to negotiate with the Mexican government.
Former president Donald Trump's administration first instituted the policy in 2018 in response to a surge in migration along the southern US border.
The policy prevented migrants, including those seeking asylum for fear of persecution in their home countries, from being released into the US.
Democrats and immigration advocates criticised the “Remain in Mexico” policy, saying those who were stuck in Mexican border cities have faced kidnapping and other dangers.
The number of migrants caught crossing the US-Mexico border has set new records in recent months. US Customs and Border Protection reported 239,000 enforcement encounters this year, data shared by the department show.
This is roughly 50,000 more encounters than at the same time last year.
Mr Biden's immigration policies have been slammed by Republicans, who argue that Mr Trump's “Remain in Mexico” policy slowed down unlawful migration.