The Treasury Department on Friday announced new sanctions against the Islamic State’s chief supplier of drone technology.

The move will freeze the U.S. assets of a Yunus Emre Sakarya, who has procured more than $500,000 worth of unmanned aerial vehicles for ISIS since 2015, when the group controlled broad swaths of Syria and Iraq. The sanctions designation was announced as part of a broader effort to crack down on ISIS aides around the world.