Haiti is experiencing a "catastrophe", President Rene Preval has said after the country was hit by three storms in quick succession.
The storms have killed some 170 people and forced thousands from their homes.
Mr Preval said the latest storm, Hanna, could cause even more damage than Storm Jeanne that killed 2,000 people in 2004.
Haiti's second city, Gonaives, was severely affected by Hanna. Many homes were deluged, and families were forced to pack up and flee.
But there was some good news from Gonaives. Chantal Pierre managed to give birth with the help of UN peacekeepers.
Some parts of the country are under several metres of water, and in some cases residents have been forced to climb onto roofs.
Many crops have been destroyed, threatening a food crisis in the coming days.
UN peacekeepers and aid workers have struggled to reach stranded survivors and say they cannot rescue anyone because of the severity of the damage.
Hanna, which has now been downgraded to a tropical storm, is expected to reach the US coast on the weekend.