A standoff between Chinese and Vietnamese ships near the Paracel Islands put a fresh spotlight on long-standing and bitter maritime disputes.
The stakes are high the South China Sea is one of the world's most important shipping lanes, rich in fish and believed to contain significant oil and gas reserves.
However, some members of the Association of Southeast Asian Nations are wary of upsetting their political and economic relationship with their giant neighbor and regional powerhouse.
While little was expected beyond a joint statement made by foreign ministers yesterday who expressed concern and called for self-restraint, Philippine President Benigno Aquino III made it clear before the leaders sat down today that he wanted firmer action.
More From This Section
He said he would raise his country's own territorial dispute with Beijing, while calling for support to resolve its conflict through international arbitration.
"Let us uphold and follow the rule of law in resolving territorial disputes in order to give due recognition and respect to the rights of all nations," Aquino said in a statement.
Vietnam has protested China's oil rig deployment close to its shores, and sent a flotilla to confront about 50 Chinese vessels protecting the facility.
Vietnam says the islands fall within its continental shelf and a 200-nautical-mile exclusive economic zone. China claims sovereignty over the area and most of the South China Sea a position that has brought Beijing in conflict with other claimants, including the Philippines and Malaysia.
The United States has criticised China's latest action as provocative and unhelpful.
Chinese Foreign Ministry spokeswoman Hua Chunying responded by saying that the issue should not concern ASEAN and that Beijing was opposed to "one or two countries' attempts to use the South Sea issue to harm the overall friendship and cooperation between China and ASEAN," according to state-run Xinhua News Agency.