A US warship sailed near the Chinese-controlled Paracel Islands in the disputed South China Sea on Friday in a freedom of navigation operation, the US Navy said, the first such mission under President Joe Biden's new administration.
The busy waterway is one of a number of flashpoints in the US-China relationship, which include a trade war, US sanctions, Hong Kong and Taiwan.
China has been infuriated by repeated US sailings near the islands Beijing occupies and controls in the South China Sea. China says it has irrefutable sovereignty and has accused Washington of deliberately stoking tensions.
The US Navy's 7th Fleet said the USS John S. McCain "asserted navigational rights and freedoms in the vicinity of the Paracel Islands, consistent with international law".
The freedom of navigation operation upheld the rights, freedoms and lawful uses of the sea recognised in international law by challenging the "unlawful restrictions on innocent passage imposed by China, Taiwan, and Vietnam", it said.
China took full control of the Paracels in 1974 after a short battle with South Vietnamese forces. Vietnam, as well as Taiwan, continue to claim the islands.
Malaysia, Brunei and the Philippines have claims to other parts of the South China Sea, where China has been building artificial islands and constructing air bases on some of them.
The same US ship involved in this mission earlier this week transited the sensitive Taiwan Strait, drawing an angry response from Beijing.
Last month a US aircraft carrier strike group entered the South China Sea for what the Navy said was routine operations.