Costa Rica and Panama are coordinating to expedite southbound migrant transit through their countries along the same route that carried hundreds of thousands north in recent years.

Panama said on Tuesday that it's working to formalize a route long used to smuggle migrants on the way to the U.S., which is now being increasingly used to return migrants to South America in a reverse flow triggered by the Trump administration.

Officials in Costa Rica and Panama are confiscating migrants' passports and cellphones, denying them access to legal services and moving them between remote outposts as they wrestle with the logistics of a suddenly reversed migration flow.