The ministers of the Association of Southeast Asian Association were in the Cambodian capital of Phnom Penh for their annual meeting, which was also attended by, among others, U.S. Secretary of State Hillary Clinton and Chinese Foreign Minister Yang Jiechi.
The dispute over the resource-rich and strategic South China Sea relates to overlapping territorial claims by China and some of the ASEAN members. With rising concerns over China's growing military and economic might, the sea issue has assumed greater regional significance.
The code of conduct agreement had been sought as a way to avoid future conflicts over the sea but The New York Times reported the parties failed in the effort without even a basic diplomatic communique.
The report said Clinton, who met with the ASEAN ministers, later indicated in remarks apparently directed at China that it was important to resolve the disputes "without coercion, without intimidation, without threats and without use of force."
Divisions within ASEAN among those countries that are dependent on China and those willing to challenge the Communist giant on the issue were seen as reasons for the failure to reach an agreement.
The Voice of America quoted Clinton that the United States will not take sides on the sea issue but wants peace and stability there.
The territorial disputes in the South Sea have heated up lately between the Philippines and China and Vietnam and China. These developments come as the United States shifts its foreign policy pivot to the Asia-Pacific region to counter China's growing influence.
The Times said the administration of U.S. President Barack Obama has made it known that freedom of navigation in the South China Sea is vital for commerce.
Clinton, noting the United States is "a resident Pacific power," was quoted as saying, "No nation can fail to be concerned by the increase in tensions, the uptick in confrontational rhetoric and disagreement over resource exploitation."
China opposes a regional forum setting to settle the sea dispute, insisting it will deal with each country individually, which raises questions about concluding a code of conduct agreement, which the United States supports.
In an opinion piece, The Wall Street Journal said the surest way to "press Beijing to negotiate a reasonable settlement" is for ASEAN to present a united front on such questions as a procedural code of conduct.
The report said Clinton "again called for such a multilateral approach, despite Beijing's preference for bilateral talks in which it can try to overwhelm or bully its smaller neighbors one by one."
Clinton praised Asian leaders Wednesday for helping advance the "common interest of all stakeholders in the Asia Pacific." Arriving in Phnom Penh Wednesday for the regional forum, Clinton said, "I understand that ASEAN faces a variety of challenges and even growing pains as it adapts and takes on new responsibilities."
The forum comes as the United States is focusing more in the Asia-Pacific region, where China's growing military might remains a concern to neighboring nations. China's claims of sovereignty over the resource-rich South China Sea are another major security concern.