Thousands of people are now struggling on a neighbouring island in fierce heat with limited food, water and shelter.
More than 3000 refugees arrived on the island of Espiritu Santo from Ambae on boats yesterday and a similar number were expected today.
Foreign Minister Gerry Brownlee said the government had now received a formal request from the Vanuatu government for specific assistance and would send another $250,000 worth of supplies to the country.
"Tomorrow morning a C-130 from the New Zealand Airforce will take off with those supplies," Mr Brownlee said.