At least eight dead after Cyclone Pam

At least eight people have died in Vanuatu, a senior aid official says, in one of the strongest tropical cyclones to have hit the South Pacific.

It comes amid unconfirmed reports that more than 40 people may have perished elsewhere in the country as a result of Cyclone Pam.

The official death toll in Port Vila stands at six, with another 20 confirmed injured, according to Vanuatu's National Disaster Management Office.

One person has also died in Papua New Guinea's West New Britain province after a tree fell onto a house during strong winds driven by the storm.

Australia is ready to assist as the cyclone-ravaged nation assesses the aftermath of one of the worst storms in the island nation's history.

New Zealand is now preparing for the impacts of the cyclone as the country's north is expecting heavy rain, gales and high seas from Sunday night. This could cause power cuts, widespread flooding and damage.

Although the front of the storm has started to weaken, it will remain "an intense storm with hurricane force winds near the centre" out to midnight Sunday, the MetService told media.

Residents in Northland, Auckland, Coromandel, Bay of Plenty, northern Hawke's Bay and Gisborne are being urged to prepare for the storm.

Tropical Cyclone Pam hit the South Pacific island chain on Friday, devastating homes and bringing flooding, high seas and winds in excess of 250km/hr.

Though the full extent of the damage in Vanuatu is unknown, the UN had unconfirmed reports of 44 people killed in just one province while aid agencies described scenes of destroyed homes, downed trees and blocked roads as a result of Super Cyclone Pam, a maximum category five storm.

"We stand ready to support with whatever is needed, working with our partners, New Zealand and other countries in the Pacific," Foreign Minister Julie Bishop said on Saturday.

• 'Once in a lifetime': Cyclone Pam rips through Vanuatu

Ships wrecked after Cyclone Pam tore through Vanuatu. Photo: UNICEF

Witnesses have described scenes of devastating, with home stripped to their foundations and damage to the main hospital in the capital, Port Vila.

Ms Bishop said there were probably 3000 Australians in Vanuatu at any one time, but the government had not received any reports regarding Australian citizens.

Late Saturday night senior aid officials confirmed at least eight people had died in Vanuatu.

Vanuatu's President Baldwin Lonsdale led appeals for international assistance, telling delegates at a UN conference on disaster risk reduction in Japan that he spoke with a "heart that is so heavy".

"I stand to appeal on behalf of the government and people of Vanuatu to the global community to give a lending hand in responding to these very current calamities that have struck us," Lonsdale said.

"Fellow heads of state, governments, and development partners, we have all experienced a form of disaster at one time or another. Today we appeal for your assistance."

Aid agencies were scrambling for information and preparing to send teams to Vanuatu, whose main island is home to more than 65,000 people, with a UN disaster assessment and coordination team expected to arrive late Sunday.

Whole towns have been "literally blown away" by the destructive force of Cyclone Pam, witnesses said after the tropical cyclone smashed into the island nation on Friday.

The category five storm brought winds of more than 250km/h as it slammed into the island.

World Vision worker Chloe Morrison says the deadly storm has wrought catastrophic damage.

She spent a terrifying night bunkered down in a house in Port Vila, the nation's capital, with her co-workers.

"There are reports from our other colleagues of entire villages being literally blown away overnight," she told AAP.

"Local houses and leaf huts would have been picked up like confetti last night."

Tin roofs had been stripped off houses and trees uprooted, she said.

She said shelter, clean water and access to food were the main concerns.

But it was hard to get a sense of the true extent of the damage, given many of the islands had poor infrastructure before the storm hit, she said.

The Bureau of Meteorology, which has been monitoring the storm, said most parts of Vanuatu had been affected.

The storm reportedly changed course at the last minute, hitting the capital Port Vila harder than expected.

Residents evacuated in Vanuatu as Cyclone Pam reaches a category five storm. Photo: 350 Pacific/Facebook

The Red Cross says people are being assisted at dozens of safe buildings and evacuation centres across six provinces.

The organisation has established 12 evacuation centres in and around Port Vila.

People were evacuated on Friday to safe shelters in Torba, Sanma and Penama provinces in the north of the country.

CARE Australia has launched an urgent appeal for support following the ‘utter devastation’ of Cyclone Pam [ http://www.care.org.au|If you would like to help click through to contact CARE Australia.].