Chinese Premier Wen Jiabao Monday urged the 10-member Association of Southeast Asian Nations (ASEAN) and China, Japan and South Korea to further promote cooperation in the region.
Speaking at the regional summit in Phnom Penh, Cambodia, Wen also asked countries to focus on development problems and work for the early creation of an East Asian community.
He said all ASEAN nations, as well as China, Japan and South Korea should continue to step up strategic communication, deepen mutually beneficial cooperation, and stay committed to maintaining lasting peace and common prosperity in East Asia.
Chinese efforts for closer regional ties, however, were challenged by a decision by Japanese and Philippine representatives to bring up the South China Sea issue at the summit.
"Prime Minister Noda raised the issue of the South China Sea, noting that this is of common concern for the international community, which would have a direct impact on peace and stability of the Asia-Pacific," a Japanese government statement said after Noda met leaders from ASEAN.
That followed a statement on Sunday from Kao Kim Hourn, a Cambodian foreign ministry official, who said Southeast Asian leaders "had decided that they will not internationalize the South China Sea from now on."
Philippine President Benigno Aquino on Monday also claimed that no such consensus had been reached and he would continue to speak out on the global stage.
"There were several views expressed yesterday on ASEAN unity which we did not realize would be translated into an ASEAN consensus," he said.
Temperatures could rise again when Obama joins the East Asia Summit, a two-day event also involving the leaders of South Korea, India, New Zealand and Australia.
Washington has previously angered Beijing, and emboldened the Philippines, by calling for a legally binding code of conduct to govern their actions over the sea. China has repeatedly said it is against any involvement by nations outside Southeast Asia.