The Vanuatu Geohazards Department raised the alert level for the volcano last week after increased activity at Lombenben's Manaro Voui crater.
Communities in the northwestern and southern parts of Ambae have been worst affected with reports of buildings and trees collapsing under the weight of the ash.
Water supplies have also been contaminated and food gardens smothered.
The operations manager of the National Disaster Management Office, Peter Korisa, said assessments were still be done and affected communities might be relocated.
But he said a longer term solution was needed.
"It is quite different because it is a permanent type of hazard. So it remains on the island and it will continue. It is a slow onset, can be rapid and go slow onset hazard. So it is quite complicated. So we will see how in the future the government might try its best how to come up with some solution," he said.