Following Monday's meeting, Asean - of which Myanmar is a member - announced that it was setting up a task force to handle aid distribution.
The regional bloc had earlier come under criticism for failing to persuade Myanmar's ruling generals to overcome their suspicion of outsiders and allow foreign aid workers access to the country.
Asean officials said the agreement was the best approach to handling the crisis and called for the move not to be "politicised".
The first Asean teams are due to arrive in Myanmar on Wednesday, a day before Ban Ki-moon, the United Nations' secretary-general, is expected to land in the country.
Ban is expected to tour the hard-hit Irrawaddy delta region before returning to Yangon, Myanmar's former capital, to chair a meeting of meeting of aid donors expected to take place on Sunday.
The Myanmar government says losses from the storm have exceeded $10bn.
On Monday John Holmes, the UN's top humanitarian coordinator, toured some of the worst-hit areas of the delta region before holding talks with aid groups in Yangon.
But the United Nations said the bulk of the rest of its foreign staff were still barred from the delta.
In a statement it described conditions in the region as "terrible", with hundreds of thousands of survivors suffering from hunger, disease and lack of shelter.
The official death toll from Cyclone Nargis stands at about 78,000 but aid agencies believe the number to be higher. Another 56,000 people are still missing.
Relief agencies have warned of a mounting threat of disease and say that the most vulnerable survivors will start dying soon unless they get the aid they need.
In its latest assessment, the UN said only about 500,000 of the 2.4 million storm victims had received some form of international assistance.
"It is clear that the emergency phase is set to continue for some time," it said.
The International Federation of Red Cross and Red Crescent Societies said heavy rain fell on the delta again on Monday.
While the rain could provide those able to collect some with drinking water, for many others it "simply adds to the misery as they look forward to their 18th night in often wretched conditions" it said.
|The UN says only about a fifth of storm victims |
have received any form of aid [Reuters]
"In addition, access to already relatively inaccessible locations is set to remain very difficult."
The IFRC added that it remained concerned about the distribution of relief supplies, saying "reports indicate that in most of the bigger affected townships, basic relief and food is available but much less so in the more remote areas".
Chris Webster, a spokesman for aid group World Vision, said in neighbouring Thailand that "the need is still overwhelming the actual relief response".
"There's a huge challenge in the hands of the aid workers and we don't have all the people we need [in Myanmar]," he said.