The Department of Defence confirmed its fighter jets brought down the balloon over US territorial waters.
BBC reports China's foreign ministry later expressed "strong dissatisfaction and protest against the US's use of force to attack civilian unmanned aircraft".
Footage on US TV networks showed the balloon falling to the sea after a small explosion.
An F-22 jet fighter engaged the high-altitude balloon with one missile - an AIM-9X Sidewinder - and it went down about six nautical miles off the US coast at 14:39 EST, a defence official told reporters.
