China's President Xi Jinping has inspected the arm of the Chinese navy that operates in the South China Sea. He urged its forces to enhance the level of their training and combat readiness.

State-run China Central Television reported that Xi visited the naval forces of the People's Liberation Army's Southern Theater Command in the southern province of Guangdong on Wednesday.

During the inspection, Xi said the navy should enhance its ability to respond swiftly and properly to complex situations.

He stressed the need to resolutely defend China's territorial sovereignty and maritime rights and interests, as well as maintain stability in surrounding areas.

Xi also said the navy should further study warfare and military operations while strengthening military training under combat conditions.

China claims most of the South China Sea and has been increasing its military presence in the area. Beijing has been at odds with Manila over disputed territory there.

Xi's remarks come as the Philippines and the United States began their largest-ever joint military drills on Tuesday.

Observers say he is showing his determination not to back down on China's territorial claims amid the rising tensions.