A "Dunkirk-style operation" will be needed to get thousands of people off the island of Ambae as the eruption of the Manaro volcano continues, a Vanuatu journalist says.
The volcanic alert at the Manaro Voui crater is at level four with warnings of flying rocks, volcanic gas, acid rain and ash falls.
Yesterday, Vanuatu Prime Minister Charlot Salwa ordered the compulsory evacuation of the island by 6 October.
At least 7000 of the island's population of more than 11,000 have already been relocated from danger zones around the volcano to evacuation centres on the western and eastern sides of the island.
Vanuatu Daily Post journalist Dan McGarry said only a few hundred people so far have been taken to neighbouring Pentecost Island.
"It is going to require something approximating a Dunkirk-style operation where we're going to have to mobilise a lot of civilian marine craft in order to accommodate that large number of people in such a short period of time."
Mr McGarry told RNZ's Morning Report those evacuated so far were mostly children, pregnant women and elderly people.
The government has asked the international community to provide non-perishable food items until food from other Vanuatu islands could be obtained.
Peter Korisa from Vanuatu's Disaster Management Office said food, water and shelter for those affected was the primary concern.
Mr Korisa said the situation was frightening and stressful for communities on the island, but they were calling for people to listen out for instructions from officials.
"We don't want to create panic in this type of situation.
"What we are trying to do now is just pass the message back to them, just to keep calm and wait for anything that government would decide."
New Zealand was working with the Adventist Development Relief Agency and Vanuatu's Disaster Management Office to deliver $US325,000 worth of water, sanitation and hygiene kits to Ambae Island refugees.
New Zealand vulcanologist Brad Scott is heading to Vanuatu later today.
He told Morning Report the eruption has been escalating over the past couple of weeks.
He said he was going to help the geohazards vulcanologist team collect data and make assessments to aid the response.
"All the historic eruptions at this volcano have been relatively short, just a few weeks to months, rather than ... years to decades, so I would probably bias to a shorter eruption.
"But nature will have final say in that unfortunately."