"We are now trying to build what we call a coalition of mercy because nothing else has worked," Association of Southeast Asian Nations (ASEAN) Secretary General Surin Pitsuwan said in Washington.

"There is a consensus emerging now that ASEAN has to take the lead and ASEAN has risen to the occasion," he told a forum of the Council on Foreign Relations.

Surin said Myanmar's military junta had already agreed to issue visas to an ASEAN rapid assessment team, with some officials already on the ground and more expected to enter the reclusive nation soon.

"It is the beginning. With help and encouragement, we will accomplish our task," he said.

The government of Myanmar, which is an ASEAN member, has come under fire across the globe for refusing to allow foreign aid experts into the country to distribute badly needed relief supplies following the devastating May 2-3 storm.

Even ASEAN teams have not been welcomed.

The disaster has left around 62,000 dead or missing and British minister Douglas Alexander said reports from agencies on the ground indicated the number could rise above 200,000.