Border agents have been told to explicitly target Spanish speakers and migrants from Latin America in carrying out a Trump administration program requiring asylum seekers to wait in Mexico, according to memos obtained by The Associated Press that reveal some inner workings of a top government priority to address the burgeoning number of Central Americans arriving in the country.

The Trump administration launched the program in late January in what marks a potentially seismic shift on how the U.S. handles the cases of immigrants seeking asylum and fleeing persecution in their homeland. The program initially applied only to those who turned themselves in at official border crossings, but a memo from a division chief of the Border Patrol’s San Diego sector says it expanded Friday to include people who cross the border illegally.