The Chinese military dispatched ships and aircraft on Tuesday to warn off a United States warship that trespassed into China's territorial waters near the Xisha Islands in the South China Sea, a military spokesman said on Wednesday.

Senior Colonel Li Huamin, spokesman for the People's Liberation Army's Southern Theater Command, was quoted as saying that the USS McCampbell, an Arleigh Burke-class guided-missile destroyer in the US Navy, sailed into the territorial waters without permission from China. The Southern Theater Command mobilized its naval and air units to follow, monitor and identify the US vessel before warning it off.

The US has used so-called freedom of navigation to repeatedly flex its muscles and make provocations in the South China Sea, he said, noting such acts have demonstrated US hegemonism, its violations of international law as well as its threats to peace and stability in the area.

China has undisputable sovereignty over the islands and its surrounding waters in the South China Sea, and the Chinese armed forces are always ready to take any necessary measure to defend the nation's sovereignty and security as well as the region's peace and stability, Li said.

Last week, China refuted US media reports about a Chinese ship firing a laser at US military aircraft.

Defense Ministry Spokesman Ren Guoqiang said on Friday that the report was not truthful.

He said that in a separate incident on Feb 17, when a Chinese naval flotilla was conducting routine exercises in international waters, a US P-8A aircraft engaged in lengthy reconnaissance, circling at low-altitude despite repeated warnings from the Chinese side.

During the encounter, the Chinese warships' operation was professional and in line with international laws and common practices, while the US aircraft's behavior was unfriendly and unprofessional, severely threatening the safety of the vessels, aircraft and crew of both sides, according to Ren.

"We demand that the US immediately cease such provocative and dangerous acts, and cease making groundless accusations smearing China to avoid damaging overall relations between the two countries and armed forces," Ren stressed.