U.S. and Canadian troops rushed medical supplies, drinking water and chlorine tablets to flood-battered towns where bodies were seen floating in rising waters on Thursday. Haitians and Dominicans braced for a death toll that could reach 2,000.

About 10,000 people in villages surrounding the submerged Haitian town of Mapou remained in urgent need of help and cut off by roads devoured by mud, according to Michel Matera, a U.N. technical adviser.

"We are still having difficulty reaching them, even by helicopter," said Matera, who traveled to Mapou on Thursday. "We cannot land because of the flooding, nor can we get there on foot."

Late Thursday night, confirmed deaths in the two countries rose to nearly 1,000 with Haitian officials saying the recovery of scores of more bodies brought the toll to 579. The Dominican Republic reported 417 deaths there earlier.

To make matters worse, forecasters predicted more rain in the coming days for the southern border region of Haiti and the Dominican Republic.

"We're also fighting time because weather is turning bad again," said Marine Lt. Col. Dave Lapan, a spokesman for the U.S.-led force. Hurricane season, which marks the beginning of the rainy season, starts Tuesday.

Rain over the weekend lashed the island of Hispaniola, which Haiti shares with the Dominican Republic, sweeping away entire neighborhoods early Monday. The floods struck before dawn while people were asleep. Some watched relatives and homes carried away in torrents of mud.

In Mapou alone, 300 bodies have been found and at least 700 more people were missing and feared dead, according to Margarette Martin, the government representative for Haiti's southeast province.

U.S. Marines, traveling by helicopter, hurried to deliver drinking water and chlorine tablets to hundreds in Mapou, which was covered by more than 10 feet of water.

The U.S. troops delivered plastic tarpaulins for shelter in the Haitian border town of Fond Verettes, and Red Cross workers in the Dominican Republic put up mosquito nets to help prevent malaria and dengue fever.

Mudslides have washed out roads in southern Haiti, preventing workers from getting an accurate death toll. U.N. teams planned to bring in boats Friday to help recover bodies. If workers cannot recover the corpses in time, they could contaminate water sources.

"You can still see bodies in the water coming up," Matera said. "Palm trees are almost covered. There is a grave risk of an epidemic."

For many Haitians, it was one more disaster to pile atop the troubles weighing down on the poorest country in the Americas. The U.S.-led force, brought in to help after President Jean-Bertrand Aristide was ousted on Feb. 29, struggled to fill urgent needs while they prepared to hand over control to a U.N. force next Tuesday.

Sentheliare Veretnne, 45, a real estate salesman, said his family's small farm on the south coast was swept into the sea and he knew people who were missing.

"I had no reaction because the country is already in crisis," he said. "We have no work, there's the political situation, everything. You can't react emotionally."

Haiti has become a hazardous place for flooding and mudslides because its impoverished people constantly fell trees to make charcoal -- a practice that has left the country almost entirely deforested. Without roots to hold back the soil, rain can bring disaster.

Hans Hertell, the U.S. ambassador to the Dominican Republic, flew to the Dominican border town of Jimani120 miles west of the capital, Santo Domingo. "This situation is grim, and we're looking at ways to get more money here," Hertell said after surveying the damage Thursday.

American and Dutch Red Cross workers were helping Dominican authorities search for more bodies and treat dozens who were wounded, said Gustavo Lara, of the Dominican Red Cross.

Dominican authorities buried more than 250 bodies immediately, some where they were found and others in a mass grave. Authorities told families there was no time to identify the bodies because they were badly decomposed.

A man and boy ride past a temple in Leogane, Haiti, that once stood in a sugar cane field but is now submerged after heavy rain caused mudslides.Young men carry goods, valuables and fellow Haitians across a river near Mapou. Rescue workers are having trouble reaching many flood victims.