The head of Mexico’s immigration agency on Monday said the country will not accept migrants under 18 as they wait for the outcome of their U.S. asylum claims, a move that could disrupt the Trump administration's "Remain in Mexico" policy, the Associated Press reports. National Immigration Institute Commissioner Tonatiuh Guillen said Mexico will only accept asylum seekers aged 18 to 60 from Guatemala, El Salvador, or Honduras, and only at El Chaparral border crossing in Tijuana. He said Mexico will not extend the policy beyond that border crossing, despite the U.S. reportedly expressing an interest in doing so. The “remain in Mexico” program was set to begin last week with about 20 migrants returning to Tijuana. U.S. authorities had said they plan to bus asylum seekers to and from the border for court hearings in downtown San Diego, including an initial appearance within 45 days.