The Trump administration is seeking to curb migration from Central America by introducing new rules regarding who can claim asylum in the US.
Under the new rules, announced Monday, migrants who travel via another country before reaching the US border will be ineligible for asylum.
Migrants who have been trafficked will be exempt from the ban.
The Associated Press news agency says a legal challenge against the US restrictions is expected.
Announcing the rule change, Attorney General Bill Barr said it would deter economic migrants from exploiting the US asylum system.