'This is an issue that demands Asean's and China's collective and common approach and action, otherwise the risk of further tensions are very much ahead of us,' Natalegawa said as Asean celebrated its 45th anniversary this week.

'In the absence of a code of conduct, we may be risking more incidents in the future,' he said.

The 10-nation grouping - which includes China's four rival claimants in the South China Sea - has recently finalised a suggested code for discussion with Beijing. A comprehensive code was promised in the landmark Declaration of Conduct of Parties in the South China Sea agreed by Asean and China 10 years ago.

But Yang last month said China, which has long demanded one-on-one negotiations with individual claimants, would be willing to discuss the code in detail only 'when conditions are ripe'. Foreign Ministry officials have further fleshed out that position in recent days, even as they talk up intensifying Sino-Asean relations in other areas.

Foreign Ministry spokesman Qin Gang warned that 'some individual countries' had undermined the principles and spirit of declaration through 'provocative means' - a reference many insiders take to mean Vietnam and the Philippines, the most assertive of China's rivals in the South China Sea.

While being open to talks over the code, he said that 'China believes that all parties concerned must act in strict accordance with the [declaration] to create the necessary conditions and atmosphere for the discussion of a Code of Conduct'.

Vice-Foreign Minister Fu Ying , meanwhile, warned of 'certain Asean claimants' that had tried to impose their own stands onto the grouping.

In a wide-ranging interview with Xinhua, Fu insisted that despite the recent breakdown, Beijing remained open to talks with Asean and that all its member states would join China in working for the 'comprehensive and effective implementation' of the declaration, but also when conditions are ripe.

Ian Storey, a scholar at the Institute of Southeast Asian Studies in Singapore, said China was successfully highlighting divisions within Asean and using them 'as a pretext to not to begin discussions' on a code. 'We can see that China is trying to project the image that it is the constructive player in all of this,' he said.

The September talks were 'absolutely' not going to happen, Storey said - a view that a range of Asean envoys echoed. 'The atmosphere is too sour now. There is just no way they are going to agree on a Code of Conduct between now and November,' the scholar said.

Officials from Asean and China are due to meet in October to create a fresh communique to mark the decade since the two signed the historic declaration, the first time the grouping had completed such a formal agreement with a foreign power. Without any progress on the code, however, that exercise could prove largely ceremonial, analysts believe.

Asean Secretary-General Surin Pitsuwan has long called for a code to be completed in time to mark the 10th anniversary - a call that looks to be in vain.

China claims virtually the entire South China Sea through its controversial 'nine-dash line', dating from maps of 1947.

Vietnam and China claim the Paracel islands (called the Hoang Sa Islands by Vietnam and the Xisha Islands by China) and the Spratly Islands (called the Nansha Islands by China) in whole. Malaysia, Brunei and the Philippines, meanwhile, claim parts of the Spratlys.