Opponents also say it is being pushed through at a time when the United States, long seen as a crucial buffer against China's maritime assertiveness, is distracted by other issues and providing no real clarity about its security strategy in Asia, thus weakening ASEAN's bargaining position.
The framework has not been made public but a leaked two-page blueprint seen by Reuters is broad and leaves wide scope for disagreement.
It urges a commitment to the "purposes and principles" of the United Nations Convention on the Law of the Sea (UNCLOS) but does not specify adherence to it, for example.
A separate ASEAN document, dated May and seen by Reuters, shows that Vietnam pushed for stronger, more specific text in the framework, wanting mention of a dispute resolution mechanism and respecting "sovereignty, sovereign rights and jurisdiction".
Sovereign rights cover entitlements to fish and extraction of natural resources.
Several ASEAN countries, including Vietnam and the Philippines, have said they still favour making the code legally binding, something experts say China is unlikely to agree to.
Wang said he would not try to anticipate what the code will comprise, but said whatever is signed must be adhered to.
Robespierre Bolivar, foreign ministry spokesman of host Philippines, said the adoption of the framework symbolized the commitment to creating a "substantive and effective" code.
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