A Myanmar man sits under a fallen tree following the devastating cyclone on May 6 in Yangon, Myanmar. Officials feared the death toll could continue to soar. Photo: AP Wide World Photos

State television announced that the mourning period will begin Tuesday and be marked by flying the national flag at half-mast.

The announcement came as people remained in a state of shock at the May 2-3 storm's devastation and angry at what appeared to be an inadequate government effort to help the survivors, including its rejection of much foreign assistance.

It also follows on China's declaration of three days of mourning, starting Monday, for the more than 32,000 dead from its own disaster, an earthquake in Sichuan province just last week.

In Singapore, an emergency meeting of foreign ministers from the 10 countries of the Association of Southeast Asian Nations decided that the bloc will work with the U.N. to hold an aid donor conference in Yangon on May 25, Singapore Foreign Minister George Yeo told reporters.

In a major concession after being slammed for blocking foreign help, Myanmar agreed to open its doors to medical teams from all ASEAN countries, Yeo said.

In a potentially major breakthrough, the ministerial meeting _ which included Myanmar Foreign Minister Nyan Win _ agreed to set up an ASEAN-led task force for redistributing foreign aid.

``This mechanism will facilitate the effective distribution and utilization of assistance from the international community, including the expeditious and effective deployment of relief workers, especially health and medical personnel,'' Yeo said.

Myanmar's military regime, meanwhile, allowed the U.N. humanitarian chief into the devastated Irrawaddy delta for a brief tour Monday, a U.N. official said.

But the United Nations said the rest of its foreign staff were still barred from the delta and it described conditions there as ``terrible,'' with hundreds of thousands of cyclone victims suffering from hunger, disease and lack of shelter.

John Holmes, the U.N. undersecretary-general for humanitarian affairs, flew by helicopter to the delta before returning to Myanmar's largest city, Yangon, to meet with international aid agencies, said a U.N. official who spoke on condition of anonymity because he was not authorized to speak with the media.

U.N. Secretary-General Ban Ki-moon will also travel to Myanmar this week, and will visit the battered delta after his scheduled arrival in the country Wednesday, U.N. spokeswoman Michele Montas said in New York.

Earlier, junta leader Senior Gen. Than Shwe had refused to take telephone calls from Ban and had not responded to letters from him, Montas said.

Amanda Pitt, a U.N. spokeswoman in Bangkok, said the world body was seeing ``some progress in terms of pipelines starting to come through'' but the aid operation was still unsatisfactory.

``Clearly we're still not satisfied, which is why we keep saying we need to upscale the response. We're not satisfied with it, nobody is. We can see the situation is terrible,'' she said.

European Union nations have warned the junta could be committing a crime against humanity by blocking aid intended for up to 2.5 million survivors faced with hunger, loss of their homes and potential outbreaks of deadly diseases.

But other signs have appeared that the generals might be slowly listening to the chorus of criticism.

A team of 50 Chinese medics arrived in Yangon on Sunday night, following in the footsteps of medical personnel from India and Thailand, the official Chinese news agency Xinhua reported.

On Monday some 30 Thai doctors and nurses began working in the delta _ exceptions to the regime's ban on foreign aid workers in the area.

Myanmar's state-run media lashed out at critics of the regime's response to the disaster, detailing the junta's efforts. State television showed Than Shwe inspecting supplies and comforting homeless victims in relatively clean and neat rows of blue tents.

At least 78,000 people were killed in the storm and another 56,000 were missing.

The official New Light of Myanmar newspaper said the government's National Disaster Preparedness Central Committee will work with foreign aid agencies ``to ensure that all relief funds and supplies reach the storm victims.''

Myanmar will also work with ASEAN countries to help cyclone-stricken areas in a rehabilitation drive that will be planned over the next several days, the newspaper said, quoting Deputy Foreign Minister Kyaw Thu.

The situation remained grim in the Irrawaddy delta south of Yangon.

In the delta city of Laputta, hundreds of children covered their heads from the rain with empty aluminum plates as they lined up for food in front of a private donation center.

``Children only. Please. Children only,'' shouted a man who pushed back a crowd of adults. He explained they were feeding children and the elderly first because food supplies were limited and most adults could still fend for themselves.