（Photo: CGTN）

China has dispatched military vessels and fighter planes to warn off the missile destroyer USS Stethem that had trespassed China's territorial waters off the Xisha Islands earlier on Sunday, according to a statement by the Ministry of Foreign Affairs of China.

In the statement, spokesman Lu Kang said the act was "a serious political and military provocation."

Lu said the Xisha Islands are an inherent part of the Chinese territory and Chinese laws have explicit provisions on the entry of foreign military vessels' into the territorial.

The spokesman said the US sending a military vessel into China's territorial waters under the pretext of "navigation freedom" violated the Chinese law and relevant international law, infringed upon China's sovereignty, disrupted peace, security and order of the relevant waters and put in jeopardy the facilities and personnel on the Chinese islands.

China and ASEAN member states have worked together to improve the situation in the South China Sea, said Lu. He added the US were deliberately stirring up troubles in the South China Sea.

China has urged the US to immediately stop such kind of provocative operations, stressing it will take all necessary means to defend national sovereignty and security.

This is the second operation of its kind since US President Donald Trump took office in January. On May 25, US warship USS Dewey sailed within 12 nautical miles of Meiji Reef of China's Nansha Islands in the South China Sea, a maneuver which – according to the US – came under the “freedom of navigation” principle.