The number of migrants stuck at the Guatemala-Mexico border continues to dwindle as detentions chip away at what remains of the latest caravan, AP reports.

The first buses of migrants left Tecun Uman, Guatemala overnight to repatriate migrants to their countries. On Tuesday, Mexico began flying and busing hundreds of migrants who had crossed into the country back to Honduras.

Mexican President Andres Manuel Lopez Obrador recognized the success of his government’s strategy on Wednesday, noting that many of the migrants had begun to voluntarily return to their countries.

US Department of Homeland Security Secretary Chad Wolf commended Mexico’s actions in a statement.