China has issued its second protest in as many days over US naval activity in the region, drawing an unusually sharp response from the US 7th Fleet, which accused Beijing of attempting to assert illegitimate maritime rights.
A statement from the Chinese People's Liberation Army's Southern Theatre Command said the guided missile destroyer USS Curtis Wilbur "illegally" intruded into its territorial waters surrounding the Paracel island group in the South China Sea on Thursday.
It said Chinese forces mobilised to track and monitor the ship and "warned and expelled it."
The Paracels are also claimed by Vietnam.
China accused the US of increasing regional security risks, "misunderstandings, misjudgments, and accidents at sea."
It called the ship's manouevres "unprofessional and irresponsible," saying Chinese forces were determined to defend the country's sovereign claims while maintaining peace and stability in the South China Sea.
The US refuses to recognise China's claim to virtually the entire South China Sea and regularly conducts what it calls freedom of navigation operations to assert its right to sail in international waters.
In its lengthy response, the 7th fleet said the operation "upheld the rights, freedoms, and lawful uses of the sea recognised in international law by challenging the unlawful restrictions on innocent passage."
"The PLA's statement about this mission is false. USS Curtis Wilbur was not 'expelled' from any nation's territory," the statement said.
"USS Curtis Wilbur conducted this FONOP (freedom of navigation operation) in accordance with international law and then continued on to conduct normal operations in international waters."
It said that China's statement asserts its "excessive and illegitimate maritime claims at the expense of the Southeast Asian neighbours in the South China Sea."
China on Wednesday issued a complaint over the Wilbur's passage through the Taiwan Strait, also calling it a provocation that undermined peace and stability in the region.
Along with building the world's largest navy and coast guard by numbers of vessels, China has fortified its island holdings in the strategically vital South China Sea and created new island outposts by piling sand cement on coral reefs and topping them with airstrips and other infrastructure.
It has ignored rival territorial claims by its smaller neighbours, including the Philippines and Vietnam, as well as an international arbitral ruling that declared most of China's claims in the South China Sea invalid.
Australian Associated Press