The Pacific nation of Vanuatu has made plans to evacuate nearly 3,000 villagers after a highly active volcano started spewing ash clouds, an official said on Monday.

The picturesque Gaua volcano, which has erupted 13 times since 1963 and has been exploding and rumbling for several months, is under close watch after a marked rise in activity in recent days.

"It's increasing in activity," said Peter Korisa, planning officer at the National Disaster Management Office. "A few days back a lot of ash clouds were released into the air. The activity isn't stable, it's increasing."

In November, about 400 people were moved from the west of Gaua island after the volcano showered their villages with ash and sulphur.

"Last year it was just some explosions and some ash falling but at the moment the activity is becoming more interesting," Korisa said.

He said some 2,700 people would be ferried to a relocation centre on nearby Vanualava island if the situation became more serious.

"We have made plans, we have identified the location but the situation doesn't warrant any evacuation unless the activity is at a stage where we have to," Korisa said.

"At the moment we're monitoring the situation and activity of the fault."

Vanuatu is on the "Pacific Ring of Fire", where the meeting of continental plates causes high volcanic and seismic activity. The latest activity coincides with a volcanic ash cloud from Iceland which has paralysed European air travel.