Southeast Asian countries called on Saturday for a hotline with China to defuse tensions over their increasingly divisive maritime territorial rows.

Association of Southeast Asian Nations secretary-general Surin Pitsuwan publicly floated the proposal for the South China Sea hotline ahead of three days of talks involving the region's leaders in Cambodia starting on Sunday.

"We can give it a sense of urgency that, if there is anything developing that we all will be phoned... trying to consult, trying to coordinate, trying to contain any possible spillover of any... incident, accident, miscalculation, misunderstanding," Surin told reporters.

Surin was speaking after Southeast Asian foreign ministers' met in Phnom Penh to pave the way for the annual ASEAN leaders' summit on Sunday.

Chinese Premier Wen Jiabao, US President Barack Obama and leaders from six other nations are scheduled to then join their ASEAN counterparts for an expanded East Asia Summit starting on Monday.

Analysts said the South China Sea disputes were set to overshadow the Cambodia meetings, during which countries will be aiming to push forward policies on human rights and opening up trade.

ASEAN members Vietnam, the Philippines, Malaysia and Brunei, as well as Taiwan, have claims to parts of the sea, home of some of the world's most important shipping lanes and believed to be rich in fossil fuels.

But China insists it has sovereign rights to virtually all of the sea, and the Philippines and Vietnam have expressed concerns that their giant Asian neighbour has become increasingly aggressive in staking its claim.

The dispute led to unprecedented divisions within ASEAN this year.

An ASEAN foreign ministers' meeting in Phnom Penh ended in July without issuing a joint communique for the first time in the bloc's 45-year history because of differences over how to handle the South China Sea issue.

The Philippines and Vietnam had wanted the communique to make specific reference to their disputes with China.

But Cambodia, the hosts of the talks and a close China ally, blocked the moves.

Surin said ASEAN members had largely healed their rifts, and were intent on ensuring the South China Sea issue did not sidetrack the Cambodia talks.

"I don't think it's going to be confrontational, I don't think it's going to be overly contentious," he said.

Nevertheless, the issue is likely to flare again on Monday with Obama keen to reassure the Philippines and other US allies.

Obama is likely to reiterate that the United States has a fundamental interest in freedom of navigation in the sea, while urging ASEAN and China to agree on a code of conduct for the area, according to analysts.

China has long bristled at what it perceives as US interference in the South China Sea, and was upset at last year's East Asia Summit in Indonesia when Obama succeeded in having the issue discussed there.

Chinese vice foreign minister Fu Ying warned on Saturday that China did not want a repeat and that the South China Sea should not be on the agenda at the East Asia Summit.

"Discussion of the South China Sea issue should return to the framework of China and ASEAN. Discussing the issue in other forums will interfere with the direction of cooperation," Fu said.

Meanwhile, ASEAN leaders are aiming to endorse on Sunday a declaration they say will promote human rights within their 10 countries but which has drawn widespread criticism.

More than 60 rights groups, including Human Rights Watch and Amnesty International, issued a statement on Thursday urging ASEAN to revise a draft of the declaration.

ASEAN members are also aiming to kickstart negotiations in Phnom Penh over a giant free trade zone with China, Japan, South Korea, India, Australia and New Zealand.

The 16 nations account for roughly half the global population and around a third of the world's annual gross domestic product.