Aid is on its way from Burma's neighbours, but more will be needed
Aid agencies are beginning preliminary assessments of the devastation caused by Cyclone Nargis when it struck southern Burma on Saturday.
It is already being seen as the worst natural disaster in East Asia since the tsunami of 2004.
Getting the right supplies to the worst hit areas will be key to preventing further loss of life. BBC News looks at the main priorities for aid workers in the coming days.
Water and sanitation
Aid agencies say the most urgent challenge is to get fresh water to those who need it. Without clean drinking water, the risk of disease spreading is the most serious concern.
Children will be especially vulnerable to diarrhoea, dysentery and even cholera. Medicines including rehydration salts and antibiotics are needed urgently.
Aid teams will also seek to get mosquito nets to the homeless to prevent the spread of malaria. There is concern too about the danger of respiratory diseases among children forced to sleep outside.
A lack of electricity is hampering the restoration of the water supply in Burma's biggest city, Rangoon, and water is being distributed by trucks.
Hundreds of thousands of people are without shelter.
Many of the victims of the disaster live in some of Burma's poorest provinces. Thousands of simple homes with corrugated iron roofs have been destroyed, and whole villages and communities have been eradicated by the cyclonic winds.
Tents and plastic sheeting will be vital to protect people from the elements in order to allow them to rebuild their homes.
The government says 95% of houses have been destroyed in the city of Bogalay, by a tidal surge 3.5m high. It says most of the city's 190,000 residents are now homeless.
Burma's military government has said the country has enough rice for domestic consumption, in spite of some damage to grain stores in the Irrawaddy delta.
"I think there was some damage to rice stored by private merchants and growers, but we have enough surplus for domestic sufficiency," said Information Minister Kyaw Hsan.
But the price of food in the main city, Rangoon, has risen sharply. The price of eggs has reportedly risen threefold and the government has warned against profiteering.
The UN food agency expressed concern that Burma would no longer able to export rice to Sri Lanka and Bangladesh to help ease shortages and damp down the current rise in food prices in the region.
Transport and supplies
A key problem will be getting aid out of major population centres into the countryside, where roads have been washed away or jammed by debris.
Aid workers say Buddhist monks and home-owners have been using hand saws and axes to clear fallen trees from roads, amid accusations that the army is not doing enough.
There is also a shortage of fuel for trucks, and again, prices are soaring.
Small boats are badly needed to get supplies into hard-hit areas through the river networks, but many small vessels were smashed by the cyclone.
Women and children
The United Nations aid agency Unicef is sending five assessment teams to three of the affected areas of the country. Women and children make up more than 60% of Burma's population and are likely to be prominent among those affected.
International agencies estimate that one in three children in Burma is malnourished, making them more vulnerable to infection.
An estimated 90% of people in Burma live on just US$1 a day. In 2000 the World Health Organization ranked Burma's overall health care system as the second worst in the world.