The United Nations reported Monday that 24 people are confirmed dead and 3,300 have been displaced by Cyclone Pam in the South Pacific archipelago of Vanuatu.

Radio and telephone communications with outer islands have not yet been established two days after what the country's president called a "monster" storm, the UN Office for the Coordination of Humanitarian Affairs said.

It said 3,300 people are sheltering in 37 evacuation centres on the main island of Efate and in the provinces of Torba and Penama. "Basic emergency rations are being provided to evacuees, including water, rice, tinned fish or meat, coffee, tea, sugar, Milo, biscuits and other items," the report said.

A spokesperson for the the department of Foreign Affairs said they were aware of 29 Canadians in Vanuatu who were potentially affected by the cyclone and that since March 16, officials have reached out to Canadians known to be in the region.

Meanwhile, military aircraft from New Caledonia, Australia and New Zealand have been conducting aerial assessments of the damage.

The latest report came as Vanuatu's president rushed back to his country, which has repeatedly warned it is already suffering devastating effects from climate change with coastal areas being washed away.

Baldwin Lonsdale told The Associated Press that Cyclone Pam destroyed or damaged 90 percent of the buildings in the capital alone. Lonsdale was interviewed in Sendai, in northeastern Japan, where he had been attending a UN disaster conference when the cyclone struck.

'I term it as as a monster'

"This is a very devastating cyclone in Vanuatu. I term it as a monster, a monster," he said. "It's a setback for the government and for the people of Vanuatu. After all the development that has taken place, all this development has been wiped out."

Lonsdale said because of a breakdown in communications infrastructure, even he could not reach his family. "We do not know if our families are safe or not. As the leader of the nation, my whole heart is for the people, the nation," he said.

Officials in Vanuatu were struggling to determine the scale of devastation from the cyclone, which tore through the nation early Saturday, packing winds of 270 km/h. Bridges were down outside the capital, Port Vila, making travel by vehicle impossible even around the main island of Efate.

Paolo Malatu, coordinator for Vanuatu's National Disaster Management Office, said officials had dispatched every plane and helicopter they could to fly over the hard-hit outer islands.

"The damage to homes and infrastructure is severe," Malatu said. "The priority at the moment is to get people water, food and shelter."

The damaged airport in Port Vila has reopened, allowing some aid and relief flights to reach the country. Lonsdale said a wide range of items were needed, from tarpaulins and water containers to medical supplies and construction tools. Those on the ground pleaded for help to arrive quickly.

City's hospital overwhelmed

The city's hospital was overwhelmed with patients, and some beds were moved outside due to fears the building is no longer safe.

"The wards have all been evacuated because of structural damage," surgeon Richard Leona told Australia's Channel 7. "We are badly needing this help. We need to get an urgent drug supply and food and also set up a mobile hospital to deal with the influx of patients coming in."

In Port Vila, smashed boats littered the harbour, and sodden piles of household belongings tangled among twisted tree branches lay where some homes once stood.

Many of the city's residents spent Monday clearing away downed trees and cleaning up what was left of their houses. Those left homeless were generally staying with loved ones whose houses had withstood the storm, or sleeping in temporary shelters provided by aid agencies, said UNICEF spokeswoman Alice Clements.

Access to food and water is an urgent concern, said Clements, who is in Port Vila. Much of the city's water supply has been tainted, so residents are boiling water to drink.

Some commercial flights have resumed, although services are limited. Georgina Roberts, New Zealand's High Commissioner to Vanuatu, said two defense force planes were sent to retrieve about 100 stranded New Zealand tourists.

Vanuatu has a population of 267,000 people spread over 65 islands. About 47,000 people live in the capital.

Hannington Alatoa, head of the Vanuatu Red Cross Society, said flyovers by New Zealand and Australian relief teams showed much of the country had been "flattened." At least half of the population has been affected, Alatoa said in Sendai.

"No trees, no foliage, no iron structures standing on the western part of Tanna (island)," Alatoa said. "People are in great need of water."

The World Health Organization said it was sending health and emergency response workers and supplies, and coordinating with UNICEF and regional governments.

Scientists say it's impossible to attribute single weather events like Cyclone Pam to climate change.

"Climate change is contributing to the disasters in Vanuatu," President Lonsdale said. "We see the level of sea rise. Change in weather patterns. This year we have heavy rain more than every year."

The cyclone also caused damage to other Pacific islands, including Kiribati and the Solomon Islands. Some homes were evacuated in New Zealand on Monday to escape flooding as the weakening storm moved past North Island.