Heads of Southeast Asian nations on Wednesday emphasized the need to "intensify efforts" on implementing the Declaration on the Conduct of Parties in the South China Sea.

"We stressed the need to intensify efforts to ensure the effective and full implementation of the DOC based on the guidelines for the implementation of the DOC," regional leaders said in a statement at the end of the 2012 Association of Southeast Asian Nations summit in Phnom Penh, capital of Cambodia.

The two-day summit also focused on Myanmar and the Democratic People's Republic of Korea. Regional leaders called for "self-restraint" over Pyongyang's plan to launch a rocket and "the lifting of all sanctions" imposed by the West on Myanmar, as Aung San Suu Kyi, chairperson of the National League for Democracy, has won Myanmar's parliamentary by-elections.

They agreed to officially launch the ASEAN Institute for Peace and Reconciliation during Cambodia's Chairmanship in 2012.

The bloc's leaders again stated the importance of the 10-year-old DOC, pledging to keep peace in the area and enhance understanding over the disputed issue. But some said their statement about the South China Sea was "weak". It used the same wording as a statement from last year's summit because member countries had trouble reaching a common position.

"The same wording just pointed out that ASEAN would not accept any extreme position," Qin Yaqing, vice-president of China Foreign Affairs University, told China Daily.

He said the statement suggested that peacefully resolving disputes with China remains a common position among ASEAN members.

Cambodian Prime Minister Hun Sen also dismissed reports of a rift among ASEAN members on how to settle overlapping maritime disputes with China. He also denied reports that China had pressured Cambodia to pull the issue off the agenda of the bloc's summit this week in Phnom Penh.

"Maybe some people think that during the ASEAN summit there is a difference of view between ASEAN and China. That is the wrong thinking," he said, adding that all parties were committed to peacefully resolving disputes.

"It is a process that one cannot abandon," he said, referring to an agreement last year between ASEAN and China on guidelines for the implementation of the DOC.

On Tuesday, Philippine Foreign Secretary Albert del Rosario said there was a "big disagreement" over whether to invite China to help draft a code of conduct, designed to prevent small incidents in the sea from escalating.

Cambodia is eager to bring China into the drafting process, but the Philippines and Vietnam say the bloc should draft a code among themselves before presenting it to Beijing.

Qin said he thought inviting China to participate in the code of conduct drafting process showed "a more positive attitude".

"Territorial issues are always complicated. It is unfair and improper that a sub-regional organization writes its own tickets without a major directly related party," Qin said.

Qi Jianguo, former Chinese ambassador to Vietnam, said he did not believe that the positions among ASEAN countries over issues relevant to the South China Sea varied greatly.

"ASEAN will work as a whole to follow the principles of the DOC. Any single statement only represents a kind of intention, not the solution."

The United States has declared a "national interest" in keeping the waterway open and recently stepped up military cooperation with the Philippines, one of the countries that has competing territorial claims with China, as part of its foreign policy "pivot" to Asia.

"Some countries hope to use the shift of Washington's strategy to balance or challenge China. But they should know this is not the right solution. And I think even the United States fully understands that," Qi said.

China Daily-AFP