The Chinese military said on Saturday that the American naval destroyer USS Hopper entered China's territorial waters without the approval of the Chinese government.
According to a post on the official WeChat account of the Chinese People Liberation Army's Southern Theatre Command, the Chinese military deployed its naval and air forces to "track, monitor and warn away" the vessel.
It went on to say that the incident "proves that the United States is an out-and-out 'security risk creator' in the South China Sea."
This latest announcement comes days after China accused the Philippines of enlisting "foreign forces" to patrol the South China Sea, referring to joint patrols held since Tuesday by Philippine and U.S. forces.
Earlier this month, the United States and China held "candid" talks on maritime issues, including on the contested South China Sea, and the U.S. side underscored its concerns about "dangerous and unlawful" Chinese actions there, the U.S. State Department said.