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.

“Treasury will continue to relentlessly target ISIS support networks, and ensure that the U.S. and international financial systems are not being exploited by terror operatives,” said Sigal Mandelker, the Treasury Department’s undersecretary for terrorism and financial intelligence.

Sakarya and his company, Profesyoneller Elektronik, weren’t the only targets of anti-ISIS sanctions on Friday. Treasury sanctioned Mohamed Mire Ali Yusuf, a “financial operative” who runs two companies in Somalia that function as a front group for terrorists.

Treasury also designated “a key facilitator for ISIS and its network in the Philippines” named Abdulpatta Escalon Abubakar. Abubakar is an ISIS financier who has also worked “procure a large amount of ammunition and arms” for terrorists in the Philippines.

The sanctions designations have notable connections to past and brewing ISIS conflicts. The ISIS drones played a prominent role in their efforts to defend Mosul and Raqqa, the so-called caliphate's capitals in Iraq and Syria, from the U.S.-led coalition that reclaimed the cities. ISIS used the drones to drop grenades on coalition forces and disrupt U.S. efforts to call in airstrikes; the attacks were also featured in propaganda videos.

“ISIS's use of unmanned aerial systems [drones] for surveillance and delivery of explosives has increased, posing a new threat to civilian infrastructure and military installations,” Marine Corps Lt. Gen. Vincent Stewart told the Senate Armed Services Committee in May.

ISIS has largely been defeated as a land-holding terrorist organization in Iraq and Syria, but lawmakers worry about an affiliate of the group gaining strength in the Philippines. Pro-ISIS fighters seized a provincial capital city and held it through a five-month siege that ended in October. That country is an important U.S. ally, but lawmakers have doubts about whether President Trump has legal authority to take action against ISIS there.

"I don't know," retired U.S. Army Gen. Richard Gross, who served as legal counsel for the Joint Chiefs of Staff under former President Barack Obama, told the House Foreign Affairs Committee when asked about Trump’s ability to target terrorist in the Philippines. “[R]easonable minds can disagree and a court or someone else may say, ‘no, that wasn't what we intended with that law.’”

The Treasury Department touted the sanctions as an important nonmilitary tool for putting a crimp in the terrorists’ activities. “The administration is committed to defeating ISIS wherever it operates, denigrating its illicit revenue streams, and pursuing all financial conduits,” Mandelker said. “Each individual and entity targeted has contributed to the spread of ISIS’s terror reach in their respective corner of the world.”