The Trump administration quietly launched an effort to make asylum seekers wait in Mexico while their cases wind through U.S. immigration courts, despite clear reservations and conflicting messages from the Mexican government.

The U.S. returned one asylum seeker to Mexico — a Honduran man — on the first day of what would be one of the most dramatic changes to the U.S. immigration system of Donald Trump’s presidency, if the policy survives an anticipated legal challenge. Carlos Gomez, 55, arrived in Tijuana around midday and asked authorities for a ride to a migrant shelter.