Hillary Clinton, the US secretary of state, has warned of more conflict in the South China Sea if China doesn't agree to a maritime code of conduct at the Asia Pacific's leading security forum in Cambodian capital, Phnom Penh.
The 10 members of Southeast Asian regional body (ASEAN) have been trying to agree on a long-stalled "code of conduct" for the disputed South China Sea, home to vital shipping lanes, to help settle overlapping claims.
The Philippines is leading a push for ASEAN to unite and draw up a code based on a UN law on maritime boundaries that would delineate the areas belonging to each country. Beijing is unlikely to accept this, however.
This push came as Beijing invited bids for exploration of oil blocks in waters claimed by Vietnam, which has sparked protests on the streets of the capital, Hanoi.
Al Jazeera's Steve Chao reports from Phnom Penh.