BEIJING — China’s military announced on Sunday that it had dispatched warships to challenge two United States Navy vessels that sailed through waters in the South China Sea that China claims as its own.
The Chinese confronted the American ships and warned them to leave, the Ministry of National Defense said in a statement posted on its website, but other details of the encounter were not immediately clear.
The American vessels — the Higgins, a destroyer, and the Antietam, a cruiser — passed within 12 nautical miles of the Paracel Islands, an archipelago in the northern part of the disputed waters of South China Sea off the coast of Vietnam.
The chief spokesman for China’s Ministry of National Defense, Senior Col. Wu Qian, said that the United States “gravely violated Chinese sovereignty.”
The high-seas confrontation, while not unprecedented, came as tensions have been rising between the United States and China on a number of fronts, from trade to the on-again-off-again talks with North Korea over its nuclear program.
In recent months, China has appeared more determined to defend its claims in the South China Sea, reinforcing and arming its bases in the Paracel Islands and farther south in the Spratly Islands, even though the various islands, reefs, shoals and other outcroppings are also claimed by Vietnam, the Philippines, Taiwan and others.
On May 18 China announced that it had for the first time landed its H-6K strategic bomber on an outpost in the Paracels, Woody Island. Earlier in the month the United States also formally protested the deployment of missiles and radar equipment on three artificial islands China has built in the Spratly Islands.
American officials accused Beijing of breaking a promise the Chinese leader, Xi Jinping, made in 2015 when he said China did not intend to militarize the disputed territories. In retaliation for the deployment, the Pentagon last week rescinded an invitation for China to participate in a multinational naval exercise this summer near Hawaii.
The two American warships involved on Sunday were carrying out maneuvers known as “freedom of navigation operations.” The operations, which the Obama administration curtailed somewhat but which picked up again under President Trump, are intended to exercise what the United States says are its rights under international law.
China, whose claims on the islands in the Paracel and Spratly Islands are not recognized, argues that passage within 12 nautical miles constitutes a violation of the country’s territory under the United Nations Convention on the Law of the Sea. In April, Chinese ships and aircraft challenged three vessels of the Australian Navy as they traveled to port calls in Vietnam.
“The United States naval vessels Antietam and Higgins entered without Chinese government permission into territorial waters” around the islands, which China calls the Xisha Islands, Colonel Wu said in the statement.
China’s military, he said, would be “firm and unwavering in its determination to strengthen sea and air operational preparedness construction” on the islands.