BEIJING — Asia-Pacific leaders meeting in Russia this week are expected to discuss how best to reconcile border disputes in the South China Sea. Vietnam, Taiwan, Malaysia, Brunei, the Philippines and China all have competing territorial claims.

Chinese patrols in contested waters, and a new Chinese garrison on a disputed island put rival claims to the South China Sea front and center at this week's forum of the Asia-Pacific Economic Cooperation.

"There is a small risk, and I think it is a growing risk, that an incident at sea could escalate into conflict involving China and one of its neighbors, and I think that is what we are all worried about," said Rory Medcalf, who directs the International Security Program at Australia's Lowy Institute.

U.S. Secretary of State Hillary Clinton says Southeast Asian nations should draft a unified code of conduct with China to resolve competing claims to the sea.

"We believe the nations of the region should work collaboratively together to resolve disputes without coercion, without intimidation, without threats and certainly without the use of force," said Clinton.

Indonesian Foreign Minister Marty Natalegawa is taking the lead.

"I had a very good, frank and candid discussion with my foreign minister of China colleague here in this very same building to call him to revert back to the diplomatic process," said Natalegawa. "I think the track is quite clear what is ahead of us, namely, we must apply ourselves to have the code of conduct done."

But the Association of Southeast Asian Nations failed to agree on a code of conduct in July. Justin Logan of Washington's Cato Institute said this week's APEC summit may do no better.

"I think bringing in different countries will create a different dynamic.  Although, in all likelihood, many of the countries that were in involved in the first go-around will be very, very reticent to get back involved again seeing the sour outcome that happened in ASEAN," said Logan.

Resolving the standoff is complicated by Chinese wariness of the Obama administration's greater military and economic involvement in Asia.  

"We have noticed the United States has said many times that it will not hold a position on the South China Sea issue," said Chinese Foreign Ministry Spokesman Hong Lei. "We hope they can keep their promises and do more things that are conducive to regional peace and stability, not the opposite."

Before APEC, Secretary Clinton tried to soothe tensions with China.

"We want to see them [China] play a positive role in navigation and maritime security issues," said Clinton. "We want to see them contribute to sustainable development for the people of the Pacific to protect the precious environment, including the oceans."

U.S. officials expect this APEC summit to endorse the need for a code of conduct over the South China Sea so that mechanisms for resolving rival claims might be in place before November's East Asia Summit in Cambodia.