Washington: The United States on Monday sent a guided-missile destroyer to challenge 12-nautical-mile territorial limits that China claims around artificial islands it built in the South China Sea.
A US defence official said the USS Lassen was nearing Subi and Mischief reefs in the Spratly archipelago, features that were submerged at high tide before China began a massive dredging project to turn them into islands in 2014.
The Lassen would be in the area for several hours in what would be the start of a series of challenges to China's territorial claims in one of the world's busiest sea lanes, said the official, who spoke on condition of anonymity.
Earlier, the official said the ship would likely be accompanied by a US Navy P-8A surveillance plane and possibly P-3 surveillance plane, which have been conducting regular surveillance missions in the region.
The patrols represent the most serious US challenge yet to the 12-nautical-mile territorial limit China claims around the islands and are certain to anger Beijing, which said last month it would "never allow any country" to violate its territorial waters and airspace in the Spratlys.
The Chinese Embassy in Washington said the concept of freedom of navigation should not be used as an excuse for muscle flexing and the United States should "refrain from saying or doing anything provocative and act responsibly in maintaining regional peace and stability."
Additional patrols would follow in coming weeks and could also be conducted around features that Vietnam and the Philippines have built up in the Spratlys, the US official said.
"This is something that will be a regular occurrence, not a one-off event," said the official. "It's not something that's unique to China."