Vanuatu police say they are closely monitoring the Lopevi eruption in Malampa province.
The emergency has also caused heavy ashfall on two nearby islands of Ambrym and Paama and has contaminated staple vegetable crops and water.
Vulcanologists have been sent to the area to assess the situation.
Acting police commissioner Arthur Caulton says once the national disaster committee gets the vulcanologist report, police are ready to respond.
"Once the National Disaster committee decides to employ police officers, then that will put all police resources and maritime and mobile and land forces responsible for survey or reporting from the affected areas."