The full extent of damage in Vanuatu from Cyclone Donna is becoming clearer as officials make contact with outlying islands.

Unicef spokesman Lachlan Forsyth said the northernmost province of Torba copped the worst of the weather.

"Certainly, we've received advice from the Government that a number of buildings have been destroyed, homes have been destroyed, others have been damaged," he said.

He said around 1000 people were moved to evacuation centres in Torba, and around 1200 in Sanma.

"Unicef along with other agencies have a lot of supplies in place in countries - that's everything from tents to education kits to medication, vaccinations, shelter."