Defense Secretary Ash Carter warned China in a pointed speech Tuesday that militarizing territorial claims over disputed small islands could produce unintended results.
"China must not pursue militarization in the South China Sea," he said at a speech at the Commonwealth Club in San Francisco. "Specific actions will have specific consequences."
China has expanded the land strips artificially, as well as placed military aircraft and surface-to-air missiles on one of the disputed islands.
“These activities have the potential to increase the risk of miscalculation or conflict among claimant states,” Carter said.
The U.S. does not take sides in the disputes but argues that they must be settled peacefully through multilateral mechanisms.
But Carter said the U.S. would continue to conduct military freedom of navigation operations in the area.
“It should be clear that the U.S. military will continue to fly, sail and operate wherever international law allows, as we do all over the world. Because the maritime domain must always be open and free to all,” he said.
“We all have a fundamental stake in the security of maritime Asia, including in the South China Sea. Nearly 30 percent of the world’s maritime trade transits its waters annually, including approximately $1.2 trillion in shipping trade bound for the United States,” he said.
Carter also slammed China and Russia for restricting Internet access and sponsoring cyberattacks.
“China and Russia, for example, are pursuing a different vision — one predicated on absolute government control of the Internet; anti-access policies like the 'Great Firewall'; state-sponsored cyber theft, including theft of intellectual property; cyber espionage; and also cyber crime,” he said.
“Clearly this approach is contrary to the values we share as a nation here in the United States.”