The airport at Port-au-Prince remains jammed with loaded planes, although aid workers are now bringing food and water to parts of the capital. Fuel shortages are also a problem for delivering aid.
“This is one of the worst humanitarian crises in decades. The damage, destruction, loss of life is just overwhelming,” said the UN secretary general, who arrived in the Haitian capital yesterday.
The UN has launched an appeal for $562m (£346m) to help 3m people for six months, while some 2m people are thought to need emergency relief.
Reports from the epicentre of the earthquake suggest damage is even more dramatic than in the capital.