The Pacific island nation of Vanuatu has lost years of development progress and must "start anew" following a powerful cyclone that destroyed or damaged 90 per cent of the buildings in the capital of Port Vila, the country's president said.

Baldwin Lonsdale, visibly weary and red eyed from lack of sleep, said he and other top government officials were preparing to return home from Sendai, in north-eastern Japan, where they were attending a disaster conference.

Australia, which along with New Zealand and France is providing rescue and relief help, offered transport from Sydney to Port Vila, his staff said.

Mr Lonsdale said the limited information he was able to get from home showed six people confirmed dead, and 30 injured and taken to hospital on Port Vila after the category 5 typhoon smashed across the Vanuatu archipelago.

He said information from other islands was not available because most communication links were still not working. But the airport in Port Vila has reopened, allowing aid and relief flights to reach the country. Port Vila is on the country's main island of Efate.

"This is a very devastating cyclone in Vanuatu. I term it as a monster, a monster. 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."

"So it means we will have to start anew again," Mr Lonsdale said.

He appealed for humanitarian aid for the homeland he called "paradise on Earth."

"Tarpaulins, water containers, medical needs, gathering tools, construction tools, all these are very important right now," Mr Lonsdale said.

Aerial surveillance showed some communities flattened, the head of the Vanuatu Red Cross Society, Hannington Alatoa, said. Mr Lonsdale said 1,000 people in Port Vila alone have been evacuated, while aid personnel from Australia, France, and New Zealand have arrived to assess the damage.

Mr Lonsdale said early warning systems and preparations in advance of the storm likely kept casualties to a minimum.

The leaders from Vanuatu found a receptive audience in Sendai, where the United Nations is working to craft a new framework for disaster risk reduction.

Japan convened the conference in Sendai to highlight progress in recovery and reconstruction following a massive earthquake, tsunami and nuclear disaster that struck its north-eastern coast in March 2011, killing more than 18,500 people.

But Mr Lonsdale said the timing of the storm, which has put Vanuatu's plight in the spotlight, was a "wonder".

"It is a miracle that we are here during this conference," he said. "This conference is about disaster risk reduction. What is happening in Vanuatu is the reality. The reality of what is happening right now."

Although communications have been partially restored in Vanuatu, Mr Lonsdale and other officials said they had not yet been able to contact their own families.

"We do not know if our families are safe or not," he said. "As the leader of the nation, my whole heart is for the people, the nation."