The US Supreme Court has given the go-ahead to Trump administration plans that severely limit the ability of migrants to claim asylum, the BBC reports.
Under the rule, people arriving via a third country must claim asylum there first before arriving at the US border.
Legal challenges against it continue but the ruling means for now it can be enforced nationwide.
The plan will affect tens of thousands of Central American migrants who travel north, often on foot, through Mexico.
The change will affect non-Mexican migrants trying to enter through the US southern border.
Curbing migration levels has been a key goal of Donald Trump’s presidency and forms a major part of his bid for re-election in 2020.