SIMI VALLEY (California) • US Defence Secretary Ashton Carter has warned that land reclamation efforts and a military buildup in the South China Sea could lead to conflict between nations in the region.
Speaking at a defence forum at the Ronald Reagan Presidential Library in California, the Pentagon chief also said America was adapting its military posture to counter increased Russian "aggression".
Appearing on the final leg of an eight-day trip that included meetings with defence ministers from several countries in the Asia-Pacific, Mr Carter said on Saturday that his concerns about the frantic pace of land reclamation in the South China Sea were broadly shared.
"The United States joins virtually everyone else in the region in being deeply concerned about the pace and scope of land reclamation in the South China Sea," Mr Carter told an audience of senior defence figures. He added that he was worried about "the prospect of further militarisation, as well as the potential for these activities to increase the risk of miscalculation or conflict among claimant states".
The Reagan National Defence Forum is an annual event that sees dozens of top US defence figures discuss America's defence policies.
Mr Carter's trip was dominated by questions over China's continued land reclamation efforts and military buildup in the South China Sea. On Thursday, he flew out to the USS Theodore Roosevelt aircraft carrier as it was sailing in the South China Sea. The enormous super-carrier was accompanied by the guided missile destroyer USS Lassen, which last month sailed past a series of islets in Subi Reef in the Spratly chain.
There, China is using dredgers to turn reefs and low-lying features into larger land masses for runways and other military uses to bolster its claims of sovereignty in the region.
The Lassen conducted a "freedom of navigation operation" as a way to rebuff China's claims. "We've done them before, all over the world. And we will do them again," Mr Carter said of the sail-by.
He said he chose to talk about Russia at the Reagan library as the Cold War was a defining theme of the late US leader's presidency.
Still, he also made some conciliatory gestures to both China and Russia, suggesting there potentially was room for both countries to be part of a broader international security structure.
"We do not seek a cold, let alone a hot, war with Russia. We do not seek to make Russia an enemy," he said, adding: "At sea, in the air, in space and in cyberspace, Russian actors have engaged in challenging activities. And, most disturbing, Moscow's nuclear sabre-rattling raises questions about Russian leaders' commitment to strategic stability, their respect for norms against the use of nuclear weapons and whether they respect the profound caution nuclear-age leaders showed with regard to the brandishing of nuclear weapons."
In an echo of some of Mr Reagan's own attempts to use technology to counter a Soviet nuclear threat, Mr Carter talked up some of America's new high-tech weaponry, including an electromagnetic railgun that can fire projectiles at an astonishing 7,250kmh.
He added that the US was modernising its nuclear arsenal, investing in new technologies such as drones and a new long-range bomber, as well as lasers and new systems for electronic warfare. The defence chief hinted at additional new weapons that would be "surprising ones I really can't describe here".