WASHINGTON (REUTERS) - A United States Navy guided-missile destroyer was followed at a safe distance by a Chinese ship as the US ship sailed inside the 12-nautical-mile limit of an artificial island built by China in the disputed South China Sea, but no incidents were reported during the passage, a US defense official said Tuesday (Oct 27).
The official said the USS Lassen also passed within 12 miles of reefs claimed by the Philippines and Vietnam during the 72-mile patrol from the north to the southwest.
Such operations, known as "innocent passage," are likely to become more frequent in the future, the official said.
"I would expect that this becomes a regular operation in the South China Sea," the official said. "This type of operation shouldn't be seen as provocative."
The US Navy patrol, which drew an angry rebuke from Beijing, was the most significant US challenge yet to the 12-nautical-mile territorial limits China asserts around the islands in the Spratly archipelago and could ratchet up tension in one of the world's busiest shipping lanes.
The US defense official said the trip took the Lassen within 12 nautical miles of Subi Reef, but not a second man-made island known as Mischief Reef.
The Lassen had been followed for weeks by Chinese intelligence-gathering or navy ships, and one of the ships did following the Lassen during its patrol, the official said.
Additional patrols were likely in the region, the official said, but gave no timing for the next such freedom-of-navigation exercises. The US Navy last went within 12 miles of Chinese-claimed territory in the Spratlys in 2012.
Both Subi and Mischief Reefs were submerged at high tide before China began a dredging project to turn them into islands in 2014.
Under the UN Convention on the Law of the Sea, 12-nautical-mile limits cannot be set around man-made islands built on previously submerged reefs.
"We're a global nation and we need to be able to operate where we're legally allowed to operate," said the official."That's why you do these kind of missions."
Chinese ships passed within 12 nautical miles of the US-controlled Aleutians Island about six weeks ago, the official noted.
"Nations routinely come within those 12 nautical miles. If you couldn't do innocent passage, it would make transiting by sea really cost-prohibitive and difficult," the official said.