Beijing (AFP) - Beijing on Wednesday accused the United States of a "provocative" act by sending a warship into disputed territorial waters in the South China Sea.
The USS McCampbell missile destroyer sailed near the Paracel Islands on Tuesday without authorisation, according to the People's Liberation Army.
The Paracel Islands are a chain of disputed islands and reefs in the South China Sea, claimed by China, Taiwan and Vietnam.
"Under the guise of 'freedom of navigation', the US has repeatedly flexed its muscles, been provocative and stirred up trouble in the South China Sea," PLA Southern Theatre Command spokesman Colonel Li Huamin said.
"This is a hegemonic act that violates international law, and ... threatens the peace and stability of the South China Sea."
PLA Navy forces tracked and identified the ship before warning it to leave, the statement said.
The US Navy 7th fleet confirmed the freedom of navigation operation.
"Unlawful and sweeping maritime claims in the South China Sea pose an unprecedented threat to the freedom of the seas," said US Navy 7th fleet spokeswoman Commander Reann Mommsen in an emailed statement.
"By conducting this operation, the United States demonstrated that these waters are beyond what China can lawfully claim as its territorial sea, and that China's claimed straight baselines around the Paracel Islands are inconsistent with international law."
In recent years, Beijing has stepped up its territorial claims in the South China Sea by building numerous artificial islands and a heavy military presence, making it a flashpoint for geopolitical tensions.
Home to large natural oil and gas reserves and some of the busiest freight waterways in the world, the area is subject to numerous territorial claims from countries including Indonesia, Malaysia, the Philippines and Brunei.
Collin Koh, a maritime security researcher at Nanyang Technological University in Singapore, said that it is rare that China, not the US, was the first to publicise the freedom of navigation exercise.
"This reflects Beijing's current policy of stressing that the PLA remains ever-ready to respond to external transgression even as China is grappling with the coronavirus," said Koh.