HANOI, Vietnam -- The Obama administration on Friday waded into thorny territorial disputes over islands in the South China Sea declaring their resolution to be a U.S. "national interest" in a move likely to irritate China.

At a regional security forum in Vietnam, U.S. Secretary of State Hillary Rodham Clinton said Washington was concerned that conflicting claims on the Spratly and Paracel island chains interfere with maritime commerce, hamper access to international waters in the area and undermine the U.N. law of the sea.

"The United States has a national interest" in resolving the claims, she said. "The United States supports a collaborative diplomatic process by all claimants for resolving the various territorial disputes without coercion. We oppose the use or threat of force by any claimant."

Clinton stressed that the U.S. doesn't support any country's claim over the islands but her comments are expected to anger China, which maintains it has sovereignty in the South China Sea, and insists on dealing with the dispute directly with other claimants away from the international arena.

She said the United States is willing to work with the all the parties, including China, Vietnam, Taiwan, Malaysia, Brunei, and the Philippines, to help negotiate an end to the disputes.

China's Foreign Ministry had no immediate comment on Clinton's remarks but U.S. officials present at the meeting said Chinese Foreign Minister Yang Jiechi repeated Beijing's long-standing position that the disputes should not be "internationalized."

Territorial conflicts in the South China Sea have occasionally broken out into armed confrontation, although China and the other claimants have sought to resolve differences peacefully under a 2002 code of conduct.

Chinese forces seized the western Paracels from Vietnam in 1974 and sank three Vietnamese naval vessels in a 1988 sea battle. The sides have yet to demarcate their sea border and many Vietnamese remain suspicious of China.

Along with rich fishing grounds, the area is believed to have large oil and natural gas reserves. Island groups also straddle busy sea lanes that are a crucial conduit for oil and other resources fueling China's fast-expanding economy.