Donald Trump’s administration announced it will deny asylum to migrants caught crossing the Mexican border illegally.
Mr Trump is expected to sign a proclamation on Friday introducing what would be a major step to restrict asylum claims.
Migrants would only be eligible for asylum if they came through official ports of entry.
The latest crackdown on illegal immigration is expected to be challenged in the courts by civil liberties groups, who argue that anyone who reaches US soil is entitled to make an asylum claim.
A senior administration official said the restriction on asylum claims will seek to address the “historically unparalleled abuse of our immigration system”.