SINGAPORE — Myanmar needs at least $1 billion over the next three years to put the survivors of Cyclone Nargis back on their feet, a U.N.-led report said Monday in the first comprehensive assessment of damage caused by the disaster that killed more than 84,000 people.

The May 2-3 cyclone caused damage estimated at $4 billion, said the report prepared by the United Nations, the Association of Southeast Asian Nations and the military junta that governs Myanmar. Damage to assets was determined to be about $1.7 billion and loss of income was estimated at $2.3 billion.

The cyclone devastated large swathes of the Irrawaddy delta and the Yangon region, killing at least 84,537 people and leaving 53,836 missing and presumed dead.

ASEAN secretary-general Surin Pitsuwan told a news conference the three parties involved in the report are seeking at least $1 billion in international aid for humanitarian relief efforts alone over the next three years to deal with "a tragedy of immense proportions."

"The task ahead is clearly enormous and will take a lot of time, a lot of effort," Surin said, flanked by the foreign ministers of ASEAN's 10 members and the United Nations' humanitarian chief, John Holmes. Myanmar Foreign Minister Nyan Win was also on the panel.

Despite the grim statistics, the report makes no mention of the junta's limited action in the first week of the disaster, which drew worldwide criticism.

The junta initially refused to allow foreign relief workers in and pictures of bodies floating in the water amid reports that soldiers were standing by idly horrified people around the world. The junta was also slammed for failing to accept international aid quickly and even physically preventing them from going to the hardest hit areas.

The military government had also insisted on full access to international relief, holding up delivery for weeks while survivors waited in desperate conditions. ASEAN helped facilitate exchanges between international donors and Myanmar's governing military junta.

Singapore Foreign Minister George Yeo, who chaired the news conference to release the report, refused to allow an Associated Press reporter's question to Myanmar's foreign minister about whether the junta felt that many lives could have been saved had it acted differently.

Yeo said that while "political questions" are relevant, the news conference was only about the assessment report.

Nyan Win said the junta hoped the international community will provide increased assistance.

"Even if we do not receive adequate assistance, we are determined to proceed with our limited resources," he said.

Members of ASEAN, the region's main bloc, usually stick to a policy of not interfering in each other's domestic affairs. But the group opened its annual meeting in Singapore Monday after issuing its strongest rebuke ever to Myanmar over the junta's failure to make progress on political reform.

ASEAN experts said the worst is still not over and the cyclone hit area remains in a state of emergency.

"People live in a very precarious condition now. If we fail to sustain the recovery efforts, they may face a second emergency," said Puji Pujiono, a recovery assessment specialist in the ASEAN team.

At a donor conference after the cyclone, participants demanded full access to storm-hit areas and an independent assessment of aid to ensure it was not being wasted or stolen.

"Both of those things are in place," Holmes said.

"It is important to have a report of this quality so that donors are sure their resources are being well spent," Holmes said, appealing to donors to "continue to be generous."

He said the U.N. had appealed for $482 million in immediate assistance but is still short $300 million.

The report paints a dismal picture of the devastation caused by the cyclone, saying it is expected to wipe out about 2.7 percent of Myanmar's projected gross domestic product in 2008. Myanmar is one of the world's 20 poorest countries with some 32 percent of its 54 million people living below the poverty line—meaning they don't earn enough to eat two meals a day.

The wall of water destroyed 450,000 homes and damaged 350,000. About 75 percent of health facilities were damaged, as were 4,000 or more schools.

About 1.5 million acres of farmlands and 60 percent of agricultural implements were destroyed. In mid-June, 55 percent of survivors had rations enough for only one day or less.

"We have tried to wipe some tears, soothe some aching hearts ... but not all," Surin said. Failure to provide them aid over the long term "will be detrimental to the very survival of the victims."

At the ASEAN meeting, foreign ministers issued a statement expressing "deep disappointment" that Myanmar's junta had extended the detention of pro-democracy leader Aung San Suu Kyi by another year, the sixth straight year that she has remained under house arrest in her dilapidated villa.

The joint statement was an unprecedented criticism of Myanmar.

Myanmar's foreign minister had earlier held out a glimmer of hope that Suu Kyi would be freed within six months at the end of the maximum six-year period that a political detainee can be held by law, Singapore's foreign minister said.

ASEAN's statements reflect its deep frustrations with Myanmar's junta, which has kept Suu Kyi in detention for 12 of the last 18 years at varying times. ASEAN is also fed up with the criticism it faces from the international community for not putting enough pressure on Myanmar.

Associated Press reporters Eileen Ng and Jim Gomez contributed to this report.