Cambodian Buddhist monks (L) walk in front of the Peace Palace during the 45th Association of Southeast Asian Nations Foreign Ministers' Meeting in Phnom Penh. Photograph: Photograph: AFP PHOTO / Tang Chhin Sothy

China may not be in ASEAN, but it’s looking more and more like an honorary member – at least where the South China Sea is concerned.

ASEAN foreign ministers yesterday took a significant step towards involving the burgeoning superpower in South China Sea discussions, adopting key elements of a Code of Conduct on behaviour in the disputed waters.

Kao Kim Hourn, secretary of state at the Ministry of Foreign Affairs, said ASEAN was now ready to meet with China over the long-awaited document that would be for “11 parties, not just ASEAN”.

“At the first meeting [on Sunday], they [senior officials] agreed that to work on the Code of Conduct ... ASEAN will meet with China to discuss the code of conduct from now on,” he said. “It is ASEAN and China.”

Senior officials, including some from China, would be involved in the final wording of the CoC, he said.

China, Taiwan and ASEAN members the Philippines, Brunei, Vietnam and Malaysia have all made claims on the resource-rich waters that have become a powder keg under the ASEAN chairmanship of China’s close ally Cambodia.

Anxieties about the CoC have intensified this year as activities in the waters increased.

In 2002, ASEAN members and China agreed on a Declaration of the Conduct of Parties in the South China Sea (DoC), but it was never fully implemented.

Yesterday’s announcement came just hours after Prime Minister Hun Sen officially launched this week’s ASEAN meetings, which included yesterday’s 45th ASEAN Foreign Ministers’ Meeting, in front of hundreds at the Peace Palace in Phnom Penh.

During his opening address, the Prime Minister said ASEAN “should give emphasis to the implementation of the DoC, including the eventual conclusion of [a CoC]”.

ASEAN secretary-general Surin Pitsuwan acknowledged yesterday there had been “rising interest” since the ASEAN regional forum in Hanoi in 2010.

“I think this has something to do with the heightened attention to the issue and the realisation and awareness that the region must be able to show the international community that it is manageable and we are trying to manage it in the best possible way,” Pitsuwan said.

The Chinese Embassy in Phnom Penh released a statement underscoring its commitment to implementing the DoC, adding that it had been engaged in “informal discussion” on how to “jointly formulate a code of conduct in the South China Sea”.

To contact the reporters on this story: Shane Worrell at [email protected]

Cheang Sokha at [email protected]