The UN today said it would resume food aid flights to Burma after earlier suspending them, while the Burmese government said it would allow one US cargo plane to land.

The development came six days after cyclone Nargis devastated the country.

UN officials said food aid flights to Burma would restart tomorrow after they were suspended when the organisation learned that the military government had impounded supplies sent on two planes earlier in the week.

Nancy Roman, the UN World Food Programme's (WFP) chief spokeswoman, said negotiations were continuing to release the shipments of high energy biscuits. The total food aid was enough to feed 95,000 people.

Burma's military government denied the goods had been seized, describing the UN's complaint as "baseless".

A spokesman said the junta had taken control of the aid to distribute it "without delay by its own labour to the affected areas".

The UN now plans to send a further two planeloads of relief supplies tomorrow.

Three Red Cross supply planes have landed in Rangoon without reported difficulties.

Speaking to reporters in Washington, a US official said Burma's ruling military junta had given the go-ahead for an aid plane to enter.

Earlier today, Ky Luu, the director of the US office of foreign disaster assistance, said the Burmese government was frustrating US efforts to help, with skilled aid workers forced to sit on the sidelines.

Earlier today, Burmese foreign ministry officials said the country would accept supplies from overseas but would control distribution itself and would not allow foreign workers in.

Ban Ki-moon, the UN secretary general, said he had "regrettably" not yet had direct talks with the Burmese government.

He warned that an even greater catastrophe could develop if the country's leaders continued to refuse entry to aid workers.

France said it would send a naval ship packed with 1,500 tonnes of aid if it gained approval from authorities.

The foreign minister, Bernard Kouchner, said the aid would be ready for departure over the weekend.

Frustration has been mounting over Burma's response to one of the worst disasters in its history.

A UN spokesman called the restrictions on foreign workers "unprecedented" in the history of humanitarian work.

The Thai prime minister, Samak Sundaravej, cancelled a trip to meet members of the junta as delays in giving visas to aid workers and landing rights for relief flights continued.

Sundaravej had offered to undertake his own humanitarian mission to break the impasse. He has been in contact with the Burmese prime minister, Thein Sein, to ask that UN staff be allowed to distribute relief supplies.

The numbers of dead and missing in Burma were likely to "escalate very dramatically", the British ambassador to Burma, Mark Canning, said.

"The figures we are now getting from authoritative sources for the number of dead and missing is between 63,000 and 100,000.

"Those numbers could escalate very dramatically, because we also know that between 1.2 and 1.9 million people are vulnerable."

He said securing access for international disaster experts was a top priority.

Bodies are floating in the floodwater, and aid agencies warned that outbreaks of disease could result in the death toll increasing further.

With roads blocked, hundreds of thousands of survivors are beyond the reach of clean water, food and shelter.

Despite the problems with access, aid agencies that already had teams operating in Burma before the cyclone struck are delivering some relief.

Action Aid, CARE International, Christian Aid, Merlin and Save the Children said they were handing out food, water, medicine, blankets and other basic supplies to thousands of victims.

The Disasters Emergency Committee, which co-ordinates appeals for 13 major aid agencies, said it had raised more than £2m from the British public.