Scheduling glitches led an immigration judge to deny a Trump administration request to order four migrants deported because they failed to appear for initial hearings in the U.S. while being forced to wait in Mexico.

The refusal Wednesday by Judge Scott Simpson was a setback for the administration's highly touted initiative to make asylum seekers wait in Mexico while their cases wind through U.S. immigration courts.

One migrant in the San Diego court had a notice to appear at the end of March but later learned that he was supposed to show up Wednesday. He said he barely made it.

The judge asked the administration to file a brief by April 10 that explains how it can assure migrants are properly notified of court appointments.