The Chinese military has urged the United States Navy to stop provocative and risky actions in the South China Sea in order to avoid accidents, a military spokesperson said Friday.

The US littoral combat ship Gabrielle Giffords and destroyer Wayne E. Meyer entered the adjacent sea area of the Nansha Islands and the territorial waters of the Xisha Islands, respectively, on Wednesday and Thursday without the Chinese government's permission, said Senior Colonel Li Huamin, a spokesman for the Southern Theater Command of the People's Liberation Army.

In response, the command mobilized air and maritime forces to identify and warn the US ship to leave in accordance with laws and regulations, Li said.

The US military has frequently sent planes and vessels to the South China Sea recently, and the Chinese military has urged it to stop such provocative and risky actions to avoid possible accidents, Li said.

China has undisputable sovereignty over the islands and its surrounding waters in the South China Sea, and the Chinese military has the resolution and ability to protect its national sovereignty and security, as well as maintain peace and stability in the region, he added.