The CIA under President Donald Trump has been covertly flying MQ-9 Reaper drones over Mexico to spy on drug cartels, current and former officials familiar with the matter told CNN, part of Trump’s dramatic reorientation of national security assets to the US southern border.

Mexico’s president said Wednesday that U.S. drone flights were part of a collaboration that has existed for years between the two countries, after U.S. media reported increased cross-border aerial surveillance of drug cartels.

The covert program, begun during the Biden administration and stepped up by President Trump, is hunting for the location of fentanyl labs.