UN chief Ban Ki-moon slammed the “unacceptably slow” response of the junta to the disaster and urged the generals to accelerate aid distribution.

The US military transport plane laden with emergency supplies was permitted to land by the ruling junta, which has been condemned for stalling the disaster response, and two more US flights are due to arrive on Tuesday.

“We know that it is a small salve for a much larger wound. More has to get into Burma. More has to reach the areas that have been hardest hit,” said US ambassador to Thailand Eric John, using the country’s former name.

“It is absolutely critical that disaster response specialists be allowed into Burma. It is important that we and the international community be allowed to help the victims of this unimaginable horror.”

The flow of international aid into the disaster zone of Myanmar, which says 62,000 people are dead or missing, has increased in the past two days, but relief agencies say much more is needed to avert a humanitarian catastrophe.

“Today is the 11th day since typhoon Nargis hit Myanmar,” Ban told a press conference. “I want to register my deep concern and immense frustration on the unacceptably slow response to this grave humanitarian crisis.”

State television raised the death toll by some 3,480 to 31,938 with another 29,770 still missing. The United Nations says more than 100,000 are likely to have been killed.

The UN also said the relief operation was only at 10 percent of the level needed to bring water, food and supplies to desperate survivors, and that just 20 percent of the food required was making its way in.

In Yangon, the country’s main city, the UN food agency’s rice warehouse was empty.

“I would urge that we don’t judge the success of this operation by flights arriving alone,” Richard Horsey, a spokesman for the UN’s humanitarian arm, said in Bangkok.

“This is a huge disaster,” Horsey told AFP TV in an interview. “It would overwhelm the capacity of any country.”

Deeply suspicious of any outside influences that may undermine their total control, the generals reiterated that foreign experts — who have the know-how to oversee the relief effort — would not be put in charge.

“If we do not act now, and we do not act fast, more lives will be lost,” said Catherine Bragg, the UN’s deputy emergency relief coordinator.

British Prime Minister Gordon Brown condemned the curbs as “completely unacceptable”, and urged the regime to allow aid agencies “unfettered” access, while Ban called on Myanmar to expedite visas for relief personnel.

A US delegation led by Admiral Timothy Keating, chief of the US Pacific Command, held talks with senior junta leaders when they touched down on the C-130 military transporter in Yangon.

They said they held a “cordial meeting” but failed to win permission for a far broader US relief effort in Myanmar, including navy ships and helicopters that could deploy in the Irrawaddy Delta hardest-hit by the May 3 storm.

“I hope we could lay the groundwork for a broad US united effort. I believe our discussions were a good first step,” said Henrietta Fore, an administrator with the US Agency for International Development (USAID).

Ten days after the tragedy struck, bloated corpses are still floating in the water, disease is breaking out among survivors with little food or shelter, and many say the government has given them nothing.

“We have not got any aid from anyone,” said Man Mu, a mother of five in one of the thousands of tiny delta villages that were pulverised by the storm. One of her children was swept away in the disaster.

“We only have the clothes we are wearing. We have lost everything.”

A Western diplomat in Yangon said there were reports of extensive dysentery outbreaks, and that cholera, typhoid and malaria could follow quickly.

“There’s no evidence of a major spread yet but some villages and communities have been quarantined, no one is going in or out, to try to prevent the spread of disease,” he told AFP.