The world community told Myanmar on Sunday to focus on saving lives more than three weeks after the cyclone tragedy and stop preventing foreign aid workers from reaching the disaster zone.

UN Secretary General Ban Ki-moon led calls for Myanmar to make good on a pledge to let outsiders in, with 2.4 million desperate survivors still short of food, water and shelter - and many at risk of dying from hunger or disease.

Officials put the best possible spin on the day-long meeting of representatives from dozens of nations, aid agencies and the secretive military regime, which has enraged world opinion with its handling of the catastrophe.

Ban called the event an "important exercise for building greater trust and cooperation" between Myanmar and the outside world, although participants said it was unclear how much money was actually pledged.

The final number was believed to be far short of the 10.7 billion dollars Myanmar last week indicated it would seek.

In comments echoed by most nations on hand, Ban rejected Myanmar's insistence that the emergency relief phase was over and that it was now time to focus on rebuilding the devastated areas of the Irrawaddy Delta.

"I expect the relief effort will run for several months, probably six months at least, as we feed and care for those who have lost everything," Ban said to open the meeting, which was attended by Myanmar's Prime Minister Thein Sein.

"I ask all of us to keep our eye firmly on the immediate objective - saving lives."

Making the first visit of a UN secretary general to Myanmar for more than four decades, Ban held talks with military leader Than Shwe on Friday - and announced the general had agreed to let in all foreign aid workers.

But more than three weeks after the May 2-3 cyclone, which left more than 133,000 dead or missing, access to the area has been extremely limited - and nations pressed the regime to make good on its word.

"There was a very clear message from the participants at the conference that they want to see the promises that have been made translated into reality," said John Holmes, the UN's top emergency relief official.

Thein Sein said Myanwar would accept foreign workers, but appeared to link their admission with rebuilding work in particular.

"For those groups who are interested in rehabilitation and reconstruction, my government is ready to accept them, in accordance with our priorities and the extent of work that needs to be done," Thein Sein said.

"We will consider allowing them if they wish to engage in rehabilitation and reconstruction work."

Upon his return to Thailand from Yangon on Sunday, Ban told reporters: "I sincerely hope they will honour their commitment."

Nations at the conference warned they would push the junta to get aid workers in.

The United States and France, which have military ships loaded with aid off Myanmar that have been refused by the junta, said the regime had to let disaster experts into the delta to assess the situation and help with relief.

"These requests are not unusual, but rather established practice readily accepted by other nations around the world when they are confronted with a natural disaster of this magnitude," said US charge d'affaires Shari Villarosa.

The storm washed away entire villages and ruined crucial rice fields that are essential to feed the impoverished nation. The European Union's top aid official has already warned there could be a famine ahead.

Despite the scope of the devastation and accounts from survivors that many villages still have not got government help, the regime gave the conference a particularly precise picture of the situation on the ground.

Planning Minister Soe Tha showed delegates a chart that said 665,271 ducks, 56,163 cows and 1,614,502 chickens had been lost in the storm - along with 35,051 acres of fish ponds and 22,200 metric tonnes of beef.

The United Nations and the Association of Southeast Asian Nations (ASEAN), the co-hosts of the donor conference, have approval to coordinate an expanded aid operation.