PORT-AU-PRINCE • The full scale of the devastation in hurricane-hit Haiti became clear as the death toll surged near 900, three days after Hurricane Matthew levelled huge swaths of the country's south.

The number of deaths in Haiti, the poorest country in the Americas, jumped to at least 877 on Friday as information trickled in from remote areas previously cut off by the storm, according to a Reuters tally of death tolls given by officials.

Matthew blasted Haiti's western peninsula on Tuesday with 233kmh winds and torrential rain.

Some 61,500 people were in shelters, officials said, after the storm hurled the sea into fragile coastal villages, some of which are only now being contacted. Aerial footage from the hardest-hit towns shows a ruined landscape of metal shanties with roofs blown away and downed trees everywhere. Mud from overflowing rivers covered the ground.

In the farming village of Chantal the mayor said 86 people died, mostly when trees crushed houses. He said 20 others were missing.

"A tree fell on the house and flattened it. The entire house fell on us. I couldn't get out," said 27-year-old driver Jean-Pierre Jean-Donald.

"People came to lift the rubble, and then we saw my wife who had died in the same spot," said Mr Jean-Donald, who had been married for only a year. His young daughter stood by his side, crying.

With cellphone networks down and roads flooded, aid has been slow to reach hard-hit areas. Food was scarce and at least seven people died of cholera.

Mr Herve Fourcand, a senator for the Sud department, which felt the full force of Matthew's impact, said several localities were still cut off by flooding and mudslides.

A ship carrying nine containers of food and medical supplies was headed for Dame Marie, further west in Grand'Anse department.

"It's probably the hardest hit department and the conditions don't allow for a helicopter to land," Interior Minister Francois Anick Joseph said. "So we're doing our best to help those affected."

Convoys were headed to other affected areas by land, sea and air, he said, including two helicopters provided by the US military to transport 50 tonnes of water, food and medicine elsewhere in Grand'Anse.

The storm is expected to rekindle debate about global warming and the long-term threat posed by rising sea levels to low-lying cities and towns. Up to 80 per cent of crops have been lost in some areas, said the United Nations Office for the Coordination of Humanitarian Affairs.

About one million people are in need of urgent assistance, said humanitarian group Care France, adding: "They have nothing left except the clothes on their back."

The United States was sending a navy ship, the USS Mesa Verde, whose 300 marines will add to the 250 personnel and nine helicopters already deployed to Haiti.

France announced it was sending 60 troops, with 32 tonnes of humanitarian supplies and water purification equipment. Venezuela, in an economic crisis itself, swiftly sent three loads of relief supplies and food.

But large-scale international aid programmes in place since an earthquake devastated Haiti in 2010 have also been criticised for failing to build local capacity while spending millions of dollars on their own short-term programmes.

AGENCE FRANCE-PRESSE, REUTERS