U.S. officials want to roll out the program at the San Diego border crossing to deal with the caravans that have become a source of frustration for Trump, but they envision it could be expanded to another five to seven crossings along the U.S.-Mexico border. Senior U.S. officials said they want more assurances on how Mexico intends to keep asylum-seekers safe and to ensure they don't get deported back to Central America before their asylum claims get resolved.