China has protested against a US Navy warship’s passage near contested islands in the South China Sea, vowing to take action to protect Beijing’s interests in the area. The warning from Chinese foreign ministry spokeswoman Hua Chunying on Wednesday came a day after US guided-missile destroyer USS Chafee sailed within 16 nautical miles of the Paracel Islands, which are claimed by Beijing, Taipei and Hanoi. Hua said the mission was dangerous and violated China’s sovereignty, prompting Beijing to send military vessels and fighter jets to warn off the Chafee. “The US destroyer’s behaviour violated Chinese law and relevant international law, severely harmed China’s sovereignty and security interests, and threatened the lives of both sides’ frontline personnel,” Hua said. US destroyer sails near disputed Paracel Islands in the South China Sea She said China had lodged “stern representations” with the United States, and urged Washington to respect Beijing’s sovereignty and security interests. The Chinese defence ministry said the operation would affect trust between the Chinese and US militaries, and could trigger “unwanted incidents”. “In the face of repeated provocation by the US forces, the Chinese military will further strengthen preparation for combat at sea and in the air and improve the defences to resolutely defend national sovereignty and security interests,” the defence ministry said. The defence ministry said China sent the Huangshan guided-missile frigate, two J-11B fighter jets and one Z-8 helicopter to warn the US vessel to leave the waters. US officials said the Chafee carried out normal manoeuvring operations that challenged “excessive maritime claims” near the Paracels. But the vessel did not go within 12 nautical miles of any island, the territorial limit recognised by the United Nations Convention on the Law of the Sea, US officials said. However Hua said the warship breached “China’s territorial line” in the region, which Beijing has drawn around the Paracel archipelago. The Pentagon did not comment directly on the operation, but said the United States carried out regular freedom-of-navigation operations and would continue to do so. In July, the USS Stethem went within 12 nautical miles of Triton Island in the Paracels, and about a month later the USS John McCain went within the same distance of Mischief Reef, one of seven artificial islands China has built in the Spratlys. Sailing within the mark is a signal that the United States does not recognise territorial claims in the area. Distracted US leaves window of opportunity for Beijing to expand power in South China Sea The Chafee’s patrol was the fourth freedom-of-navigation operation under the administration of US President Donald Trump and comes a few weeks ahead of the president’s planned trip to the region. China’s claims in the South China Sea, through which about US$5 trillion in shipborne trade passes each year, are contested by Brunei, Malaysia, the Philippines, Taiwan and Vietnam. Trump will visit China as well as South Korea, Japan, Vietnam and the Philippines. Chinese diplomatic observers said the latest patrol would dismay Beijing, but it would not affect plans for the visit, which is expected to be dominated by the North Korea nuclear crisis and the bilateral trade imbalance. “China would certainly be very unhappy about this, but it would not affect any other topic in Trump’s visit,” Renmin University international relations specialist Shi Yinhong said. “Freedom of navigation has been a US policy for decades. I don’t see the US side making a link between the South China Sea and the North Korea issue.” Analysts said the frequency and scale of freedom-of-navigation operations in the South China Sea could rise, particularly with US calls for greater international participation. “Through repeated freedom-of-navigation operations in the South China Sea, the US military is underlining its presence in the region and sending a message to other countries and its allies that it will stay in the region,” China Academy of Social Sciences researcher Tao Wenzhao said. Additional reporting by Reuters and Associated Press