China has cautioned the Philippines against escalating tensions in the South China Sea with the backing of the United States, stating that cooperation between the two nations should not be aimed at third parties.

Speaking at a press conference on Friday, Chinese foreign ministry spokesperson Guo Jiakun responded to recent remarks by U.S. Defense Secretary Pete Hegseth, who emphasized the need for the U.S. and the Philippines to strengthen deterrence against threats, including what he described as Chinese “aggression.”

“I would like to emphasize there has never been a problem with freedom of navigation and overflight in the South China Sea,” Guo said, dismissing concerns raised by the U.S. and its allies.

The South China Sea remains a flashpoint in regional geopolitics, with territorial disputes involving China, the Philippines, and several other Southeast Asian nations. The U.S. has been increasing military cooperation with the Philippines, including joint patrols and expanded base access under their mutual defense treaty, moves that Beijing has repeatedly criticized as fueling instability in the region.