US says warship sails in South China Sea amid trade tensions

The United States military has said one of its warships sailed near the disputed Scarborough Shoal claimed by China in the South China Sea, a move likely to anger Beijing at a time of tense ties between the world's two biggest economies.

The busy waterway is one of a growing number of flashpoints in the US-China relationship, which also include a trade war, US sanctions and Taiwan.

The US destroyer Preble carried out the operation on Sunday, a US military spokesman told Reuters news agency.

"Preble sailed within 12 nautical miles of Scarborough Reef in order to challenge excessive maritime claims and preserve access to the waterways as governed by international law," said Commander Clay Doss, a spokesman for the Seventh Fleet.

It was the second such US military operation in the South China Sea in the last month. On Wednesday, the chief of the US Navy said its freedom of navigation movements in the disputed South China Sea drew more attention than they deserved.

The US military has a long-standing position that its operations are carried out throughout the world, including areas claimed by allies, and they are separate from political considerations.

The operation was the latest attempt to counter what Washington sees as Beijing's efforts to limit freedom of navigation in the strategic waters, where Chinese, Japanese and some Southeast Asian navies operate.

China claims almost all of the strategic South China Sea and frequently lambasts the US and its allies over naval operations near Chinese-occupied islands.

Brunei, Indonesia, Malaysia, the Philippines, Taiwan and Vietnam have competing claims in the region.

China and the US have repeatedly traded barbs in the past over what Washington says is Beijing's militarisation of the South China Sea by building military installations on artificial islands and reefs.

China defends its construction as necessary for self-defense and says the United States is responsible for ratcheting up tension in the region by sending warships and military planes close to islands Beijing claims.

Last month, China's navy chief said freedom of navigation should not be used to infringe upon the rights of other nations.