The US military will continue to operate "wherever" international law allows, a top US admiral has said in Beijing, a week after America infuriated China by sailing close to artificial islands it is building in the South China Sea.
"International seas and airspace belong to everyone and are not the dominion of any single nation," Admiral Harry Harris said, according to prepared remarks for a speech at the Stanford Centre at Peking University.
"Our military will continue to fly, sail, and operate whenever and wherever international law allows. The South China Sea is not – and will not – be an exception," he added.
Harris is the commander of the US Pacific Command and his public declaration in the Chinese capital is a mark of US resolve over the strategically vital waterway, where Beijing has built up rocks and reefs into artificial islands with facilities for military use.
Last week, the US gave a physical demonstration of its policy, when it sailed the USS Lassen guided missile destroyer within 12 nautical miles of at least one of the land formations China claims in the disputed Spratly Islands.
Washington says it takes no position on sovereignty disputes in the region and that the sail-by was intended to protect freedom of navigation under international law, which it sees as potentially threatened by China's activities.
The USS Lassen's mission was part of the US's "routine freedom of navigation operations", Harris said, intended to "prevent the decomposition of international laws and norms".
"We've been conducting freedom of navigation operations all over the world for decades, so no one should be surprised by them," he said.
Responding to Harris's remarks, China blasted the US operation as a "blatant provocation".
Washington's call for Beijing to stop militarising the South China Sea while sending warships there itself was "an attempt to deprive China of its self-defence right as a sovereign state", foreign ministry spokeswoman Hua Chunying said at a regular briefing.
"It is a typical manifestation of hypocrisy and hegemonism."
The "ambiguous maritime claims" represented by China's "so-called 9-dash line" pose a challenge to navigation, Harris said.
Beijing claims sovereignty over almost the whole of the South China Sea on the basis of a segmented line that first appeared on Chinese maps in the 1940s.
Washington has repeatedly said it does not recognise Chinese claims to territorial zones around the artificial islands.
The contretemps comes as the world's two largest military powers work to keep their cool over the troubled waters.