The Army’s top modernization official said Monday that the Pentagon may have to relax its rules on human control over artificial intelligent combat systems to defeat swarms of enemy drones that often move too fast for soldiers to track.

All branches of the U.S. military have expressed interest in using artificial intelligence, or AI, for faster target recognition; however, the Defense Department until now has stressed that humans, not machines, will always make the decision to fire deadly weapons.

But as small unmanned aerial systems, or UAS, proliferate around the world, Army modernization officials are recognizing that swarms of fast-moving drones will be difficult to defeat without highly advanced technology.