Two US military aircraft containing a cargo of food, water and medicine have been refused entry to cyclone-hit Burma.

US ambassador Eric John yesterday said that the US and Thailand thought Burmese generals had agreed to let a US military cargo plane fly in supplies but that turned out to be premature.

"We don't have permission yet for the C-130 to go in, but I emphasise yet'," Mr John said.

The UN estimated last night that 1.5 million people had been harmed by Cyclone Nargis, with the estimated death toll now standing at 100,000.

The picture emerging from the country appears to be worse than official accounts suggest, with fears now growing for the safety of survivors given the risks from disease, exposure and malnutrition.

Aid has started to reach the capital Rangoon but calls have been made for the military government to relax restrictions on foreigners allowed into Burma.