The Chinese military sent air and naval forces to monitor and warn off a United States Navy warship that entered Chinese territorial waters in the South China Sea on Thursday, according to a Peoples Liberation Army spokesman.

Senior Colonel Tian Junli, spokesman for the PLA's Southern Theater Command, said in a statement that the USS Benfold trespassed in waters around the Xisha Islands without permission from the Chinese government.

The PLA Southern Theater Command mobilized aircraft and ships to expel the vessel.

Tian said the move seriously infringed on China's sovereignty and security, and is evidence of the US's militarization of the South China Sea.

"The incident has once again showed that the US is genuinely a creator of security risks as well as the biggest saboteur of peace and stability in the South China Sea," he said. "We demand that the US stop such provocation immediately, or else it will bear the consequences of its actions".

PLA forces remain on high alert and will protect national sovereignty and security, as well as peace and stability in the region, Tian said.

The Benfold, an Arleigh Burke-class destroyer, is part of the US 7th Fleet's Destroyer Squadron 15, the US Navy's largest forward-deployed destroyer unit.

The vessel trespassed in waters near the Meiji Reef in the South China Sea in early September, according to the PLA Southern Theater Command.