Two US warships sailed near South China Sea islands claimed by China on Sunday, two US officials told Reuters, in a move likely to anger Beijing as Donald Trump seeks its continued cooperation on North Korea.



China’s defence ministry duly expressed its opposition to what it called “provocation”. The US action seriously infringed upon Chinese sovereignty because the warships entered Chinese territorial waters without permission, the ministry said in a short statement.



Chinese ships and aircraft were sent to warn the US ships to leave, it said.

The operation was the latest attempt to counter what Washington sees as Beijing’s efforts to limit freedom of navigation in the strategic waters. The operation was planned months in advance and such operations have become routine but it came at a particularly sensitive time, days after the Pentagon uninvited China from a major US-hosted naval drill.

The US officials, speaking on condition of anonymity, said the Higgins guided-missile destroyer and the Antietam, a guided-missile cruiser, came within 12 nautical miles of the Paracel Islands, among a string of islets, reefs and shoals over which China has territorial disputes with its neighbors. The US vessels carried out maneuvering operations near Tree, Lincoln, Triton and Woody islands, one of the officials said.

Trump’s cancellation of a summit with North Korean leader Kim Jong-un has put further strain on US-China ties amid a trade dispute between the world’s two largest economies. Kim and South Korea president Moon Jae-in met on Saturday in an attempt to reinstate the summit. The Washington Post reported on Sunday that US officials had crossed into North Korean territory as preparations for Trump’s meeting with Kim continued.

Critics of the naval operations, known as a “freedom of navigation”, have said that they have little impact on Chinese behavior and are largely symbolic. The US military has a long-standing position that its operations are carried out throughout the world, including in areas claimed by allies, and that they are separate from political considerations.

Satellite photographs taken on 12 May showed China appeared to have deployed truck-mounted surface-to-air missiles or anti-ship cruise missiles at Woody Island. Earlier this month, China’s air force landed bombers on disputed islands and reefs in the South China Sea as part of a training exercise in the region, triggering concern from Vietnam and the Philippines.

The US military did not directly comment on Sunday’s operation, but said US forces operate in the region on a daily basis.

“We conduct routine and regular Freedom of Navigation Operations as we have done in the past and will continue to do in the future,” the US Pacific fleet said in a statement.

Pentagon officials have long complained that China has not been candid enough about its rapid military build-up and using South China Sea islands to gather intelligence in the region. In March, a US destroyer carried out a “freedom of navigation” operation close to Mischief Reef in the Spratly Islands.

Chinese officials have accused Washington of viewing their country in suspicious, “cold war” terms.

China’s claims in the South China Sea, through which about $5tn in shipborne trade passes each year, are contested by Brunei, Malaysia, the Philippines, Taiwan and Vietnam. The US has said it would like to see more international participation in freedom-of-navigation operations.