Migrant families who cross the southern border of the US illegally could be detained indefinitely under a new regulation announced by the Trump administration.
President Donald Trump said it would discourage migrants from coming to the US.
It replaces an agreement that set a limit on how long the government could hold migrant children in custody.
The move, announced by Acting Homeland Security Secretary Kevin McAleenan, is due to come into effect in 60 days.
Mexico has expressed concern and said it would consider legal action.
Under what is known as the Flores settlement, the government is required to release a minor from a non-licensed facility as expeditiously as possible, which has been set at 20 days.
“By closing this key loophole in Flores, the new rule will restore integrity to our immigration system and eliminate the major pull factor fueling the crisis,” McAleenan said at a news conference.
The proposal would give the government new licensing authority, allowing the use of either a state license or Immigration and Customs Enforcement detention standards, according to a DHS official, meaning families can be kept longer than 20 days.