A U.S. destroyer armed with guided missiles has sailed near disputed islands in the South China Sea in what China called a “provocation.” The operation came as U.S. officials opened talks in Beijing during a truce in the bitter trade war that has driven apart the world’s two biggest economies. The USS McCampbell carried out a “freedom of navigation” operation, sailing within 12 nautical miles of the Paracel Island chain, “to challenge excessive maritime claims,” Pacific Fleet spokeswoman Rachel McMarr told Reuters. But China was angered by the move, with Chinese Foreign Ministry spokesman Lu Kang claiming it violated Chinese and international law. The spokesman said China had sent military ships and aircraft to identify and warn off the ship, and that Beijing had lodged “stern representations” with Washington. “We urge the United States to immediately cease this kind of provocation,” he added. Donald Trump and Chinese President Xi Jinping in December agreed to halt a tariff dispute between their countries—this week’s talks mark the first round of face-to-face discussions since the 90-day truce was agreed.