A 6.2 magnitude earthquake has struck off the Pacific island nation of Vanuatu.

The US Geological Survey reports that the quake struck at 2.59pm NZ time, 101 km north-west of the capital, Port Vila.

The Pacific Tsunami Warning Centre advises that the threat of tsunami waves has now mostly passed.

The USGS says the quake was fairly shallow - at a depth of about 10km, and that no damage has been reported so far.

The quake, originally measured at 6.5, struck in the north of Vanuatu off Espiritu Santo.

Quakes are fairly common in the region. Two similar sized tremors last October and December caused no damage.

Vanuatu has a population of about 270,000, with some 44,000 living in Port Vila.