BEIJING – As the United States adopts a high-profile posture to engage in Asia, some ASEAN members have voiced reluctance to choose sides between US and China, and wishes that the two powers in the region could cooperate with each other.

"ASEAN has a stake in good relations between China and the US," speaking at China Foreign Affairs University last month in Beijing, Singapore's Ambassador-at-Large Tommy Koh told hundred of Chinese students.

"ASEAN welcomes China’s rise and seeks to deepen its comprehensive engagement with her. At the same time, ASEAN values the constructive role of the US, both economically and strategically,” the eloquent and outspoken diplomat said. "ASEAN does not wish to see the region come under the domination of any major powers."

Another Singaporean scholar, Simon Tay, Chairman of Singapore Institute of International Affairs, expressed similar view.

"I hope countries in ASEAN and Singapore don't have to make 'either… or…' choice. We really want to have 'both'," Tay said.

However, the US strong rhetoric and action has made the dynamics among multiple players in this region ever complicated.

In a long article titled 'America's Pacific Century" published on Foreign Policy, US Secretary of State Hillary Clinton stressed America’s "active role in the agenda-setting" in the region.

She said that is why President Barack Obama will attend the East Asia Summit (EAS) this month in Bali, Indonesia for the first time.

US and Russia was accepted as new members of the 18-nation EAS last year. The 10 ASEAN countries form the core of the EAS, while China, Japan, South Korea, Australia, New Zealand and India also participated.

Chinese government has made it clear that China respects the leading role of ASEAN in the Summit, and nods at the idea that the Summit be an open forum.

"China welcomes the US and Russia joining EAS and expects they can contribute to regional peace and development," Assistant Foreign Minister Liu Zhenmin said at a Tuesday briefing before the EAS.

But Liu said the EAS was not the right forum for a discussion of territorial disputes, as it is a forum for discussing economic cooperation and development.

Philippines, a vocal disputer with China over part of the South China Sea, is seeking to bring its proposal to the EAS and form a united front among ASEAN members, AFP reported.

But that union was unlikely to form, as Malaysia on Tuesday indicating it would not get on board.

"China is showing a positive step by organizing seminars and workshops, that is very positive. ASEAN should reciprocate on that," Malaysian Foreign Minister Anifah Aman told AFP.

Malaysia is one of the four ASEAN countries who hold competing claim over South China Sea. The other two are Vietnam and Brunei.

"To introduce another forum will complicate the matter further," the Malaysian Foreign Minister said, adding it was more constructive to concentrate on a non-binding 2002 code of conduct.

As the president of the Third UN Convention on the Law of the Sea, which produced UN Conference on the Law of the Sea (UNCLOS), Koh said the convention does not contain any new law on how to determine a state’s claim to sovereignty over territory.

Koh recommended the prior option is to try to resolve their sovereignty disputes through negotiations. If the negotiations prove to be fruitless, the parties should consider to resort to conciliation, arbitration and adjudication.

Well minded China's wary over US' role in the EAS, Koh said that ASEAN invited the US to join the EAS not to cite the US to against China, but to encourage the US and China to cooperate with each other and the rest of the region.

"Let me assure you that it not ASEAN's agenda to contain China. We want China to continue to grow and be prosperous because we see you as the possible blossom for the region."

"ASEAN has a stake in good relations between China and the US," Koh said, "ASEAN seeks to engage all the major and middle powers and to give them all a stake in the region's stability and prosperity."

Ouyang Yuanhua contributed to the story.