U.S. Secretary of State Hillary Clinton on Wednesday urged claimants to the South China Sea not to resort to intimidation to push their cause in the potentially oil-rich waters, an indirect reference to China ahead of a regional leaders' summit.

She said disputes in the sea lanes, a possible flashpoint in Asia, should be resolved through the 1982 United Nations Convention on the Law of the Sea, which defined rules on how countries can use the world's oceans and their resources.

That could embolden Southeast Asia's hand against China, which has said it would not submit to international arbitration over competing claims to the area, believed to be rich in natural resources and a major shipping lane.

Clinton said the United States was expecting a candid discussion of the maritime dispute at a regional forum in Bali this weekend attended by China and other Asia-Pacific leaders.

The United States does not take a position on any territorial claim, because any nation with a claim has a right to assert it, she said in Manila, while marking the 60th anniversary of the U.S.-Philippine Mutual Defence Treaty.

But they do not have a right to pursue it through intimidation or coercion. They should be following international law, the rule of law, the U.N. Convention on Law of the Sea.

China says it has historical sovereignty over the South China Sea and so supersedes claims of other countries, including the Philippines, Vietnam, Malaysia and Brunei.

The Philippines bases its claim to part of the sea on the U.N. Convention of the Law of the Sea (UNCLOS), which establishes jurisdiction over natural resources 200 nautical miles (370 km) from a country's coast.

There have been concerns about China's enforcement of its claim this year in areas claimed by Vietnam and the Philippines, including the cutting of cables on survey ships, threats to ram some vessels and breaches of airspace by military aircraft.

Smaller Southeast Asian claimants view a U.S. presence and a multilateral approach to negotiations as strengthening their stance against China's all-encompassing claim on the sea.

President Obama will reaffirm our national interest in the maintenance of peace and security in the region and internationally, Clinton said.

She said that included freedom of navigation, the rule of law and unimpeded lawful commerce, with the United States seeing UNCLOS as the overriding framework for territorial disputes.

(Writing by John Mair. Editing by Jason Szep and Ron Popeski)