The US Court of Appeals for the Ninth Circuit ruled on Tuesday that the Trump administration may require asylum-seekers to remain in Mexico while they await court proceedings in the US.

The Department of Homeland Security (DHS) issued the Migrant Protection Protocols (MPP) in January, citing public safety and national security. MPP applies to those who have stated a fear of being returned to Mexico but were assessed not to be likely to face torture or persecution if returned. Unaccompanied children, those in expedited proceedings, Mexican nationals and other vulnerable populations as assessed on a case-by-case basis are excluded from the MPP.

This MPP return system is a substitute for the traditional detention and parole system. The immigrants will wait in Mexico until an immigration judge decides their claims.

The District Court issued a preliminary injunction of the implementation of the MPP, finding that it violated the Administrative Procedure Act requirements of notice and comment and lacked statutory authorization.

The Court of Appeals overturned the preliminary injunction on both grounds. They noted that the DHS is likely to succeed as the notice and comment process does not apply to general statements of policy.