YANGON, Myanmar — After weeks of international pressure, Myanmar agreed to let in medical teams from neighboring countries and give the Association of Southeast Asian Nations some oversight of foreign aid distribution, the regional bloc announced Monday.

The junta continued to bar foreign U.N. staff from the devastated Irawaddy delta even as it bowed to criticism of its refusal to accept foreign assistance. The U.N. said after a brief tour of the delta by its humanitarian chief that conditions there were "terrible," with hundreds of thousands of cyclone victims suffering from hunger, disease and lack of shelter.

Myanmar said it will open its doors to teams from the 10 countries of the Association of Southeast Asian Nations, Singapore Foreign Minister George Yeo told reporters after an emergency meeting of ASEAN foreign ministers in Singapore.

Myanmar Foreign Minister Nyan Win also agreed to participate in an ASEAN-led task force for redistributing foreign aid, Yeo said.

"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 told a news conference.

Myanmar officials did not comment on the announcement.

The bloc will work with the U.N. to hold an aid donor conference in Yangon on May 25, Yeo said.

The junta announced a three-day mourning period for cyclone victims starting Tuesday. Inside Myanmar, people are angry at the pace of the government effort following the storm that left at least 130,000 people dead or missing.

China began three days of mourning Monday for the more than 32,000 dead from an earthquake in Sichuan province last week.

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

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.

Others, including U.N. Secretary-General Ban Ki-moon, also will be allowed into the disaster zone this week.

An Asian diplomat said Myanmar has invited at least three representatives of several countries to tour the delta Friday. He spoke on condition of anonymity because the news has not been made public.

Ban is to travel to the delta after his scheduled arrival in the country Wednesday, U.N. spokeswoman Michele Montas said in New York.

Junta leader Senior Gen. Than Shwe had refused to take telephone calls from Ban and had not responded to two letters from him, Montas said. Holmes, who arrived in Yangon on Sunday, was to deliver a third letter about how the U.N. can assist the government's immediate and long-term relief effort.

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 that 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.

At least 78,000 people were killed in the May 2-3 storm and another 56,000 were missing.

In the delta city of Laputta, hundreds of children covered their heads from the rain with empty aluminum plates as they lined up in front of a private donation center on Sunday. They were given rice, a spoonful of curry and a potato.

"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.

The relief effort has been impeded by a lack of logistical support, said Ramesh Shrestha, head of the U.N. Children's Fund in Myanmar. He said there are not enough trucks to transport supplies and a shortage of manpower to load and unload them.

"Many of those areas are still inaccessible because of the high water table, roads covered with fallen trees and bridges that are broken. The government has been clearing it but it's still not completely done yet," he 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 signs have appeared that the generals might be 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.

White House spokesman Scott Stanzel said the U.S. has sent 31 flights into Myanmar carrying water, blankets, insecticide-treated bed nets and other supplies, enough to help 100,000 people.

The aid is controlled by the Myanmar government after it lands in the country.

French Foreign Minister Bernard Kouchner said the U.N. Security Council can and should force Myanmar to allow delivery of international aid to cyclone victims.

In an editorial in the daily Le Monde published Monday, Kouchner said that the Security Council would be guilty of "cowardice" if it doesn't require Myanmar to accept the aid.

Kouchner did not detail how the U.N. could require Myanmar to allow passage of aid, or elaborate on discussions earlier this month of possible air drops of relief supplies.

Speaking later to reporters at his ministry in Paris, Kouchner said a French navy vessel packed with 1,000 tons of humanitarian aid for cyclone survivors is waiting off the coast of Myanmar as the junta debates whether to accept the goods.

Myanmar's state-run media has 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.