Haiti's government has drawn up plans to evacuate parts of the city of Gonaives, amid fears of disease in the wake of tropical storm Jeanne.
The people of Gonaives are desperate for food and water
Interim Prime Minister Gerard Latortue told the BBC that a decision would be made shortly on whether to implement the plans.
Mr Latortue said the number of people killed had risen to more than 1,500.
Aid workers have warned of the dangers of poor sanitation after the sewage system was torn apart in the flooding.
Waters have slowly begun to recede in Gonaives, the country's third largest city.
The United Nations says that it expects several hundred more bodies to be found once the full impact of the floods and landslides has been measured.
The BBC's Dan Griffiths in Port-au-Prince says aid is slowly getting through to Gonaives, but there have been angry scenes at some relief centres as large crowds have gathered, desperate to get hold of food and water.
People who may not have had food for days have been gathering around relief centres, hampering the handing out of supplies.
Relief workers describe the situation as extremely tense.
Our correspondent says UN peacekeepers already in Haiti to assist the interim government are playing a crucial role in ensuring that anger does not explode into violence.
Jeanne, currently a category two hurricane with maximum sustained winds speeds of 105 mph (165km/h), is now battering the northern Bahamas and is expected to reach Florida's east coast by later Saturday or early Sunday.
At one warehouse in Gonaives there were angry scenes as several hundred people surged against the gates of the building, desperate to get inside, our correspondent says.
Many homes have been ripped apart, forcing the owners to live on the streets or on the rooftops of houses that are still intact.
A number of children, abandoned or orphaned, were seen
roaming around the city, the International Committee of the Red Cross (ICRC) told Reuters news agency.
"I think it's fair to say that the situation is tense
because people are desperate," UN World Food Programme (WFP)
spokeswoman Anne Poulsen said.
"Many have not eaten since
Saturday night or Sunday morning."
The authorities are continuing to bury victims of the floods in mass graves.
Corpses have been dumped in a pit near Gonaives in an attempt to prevent the spread of disease, while unclaimed bodies continue to litter the city.
The roads are covered in a thick coat of mud and there is a smell of raw sewage in the air.
Survivors have to drink and cook with water from ditches containing rotting bodies and sewage.
"It's a critical situation in terms of epidemics, because of the bodies still in the streets, because people are drinking dirty water and scores are getting injuries from
debris - huge cuts that are getting infected," Francoise Gruloos, Haiti director for the UN Children's Fund was quoted as saying by the Associated Press news agency.
Haiti is chronically vulnerable to flooding and mudslides because of widespread deforestation.
Appealing for international support, UN Secretary General Kofi Annan said he was "deeply saddened by the heavy loss of life and destruction".
In the neighbouring Dominican Republic - which has retained much of its forest cover - the death toll from Jeanne was 19.