China has lashed out at the United States after two U.S. warships sailed near contested islands in the South China Sea. <br />The issue has been an on-going sticking point between the two nations... and comes at a time when Washington is seeking Beijing's cooperation on North Korea.<br />Ro Aram reports. <br /> The Higgins - a guided-missile destroyer - and the Antietam - a guided-missile cruiser reportedly sailed twelve nautical miles of the Paracel Islands on Sunday.<br />They are a group of islands and reefs in the northern part of the disputed waters of the South China Sea and are contested by China and its neighbors. <br />This forced China to send its own warships to the area to warn the American vessels to leave.<br />Other details about the encounter were not immediately known. <br />Beijing's defense ministry called the U.S. Navy's move a provocation and accused them of violating China's sovereignty. <br />In a separate statement, China's foreign ministry urged Washington to stop such actions. <br /> The U.S. did not immediately respond, but it has continuously defended its operations in the disputed waters.<br />Washington has insisted its Navy conducts regular freedom of navigation operations around the world, including in areas claimed by allies, and that they are separate from political considerations. <br />The latest operation comes at a sensitive time in U.S. and China relations, especially when they are both working on avoiding a potential trade war between them. <br /> Ties have also been strained due to President Trump's cancellation of a summit with North Korean leader Kim Jong-un.<br />Ro Aram, Arirang News. <br />