The epicenter of the earthquake was 401 km east of Tadine, New Caledonia, and was at a depth of 2 km, according to European Mediterranean Seismological Centre.
A tsunami warning has been issued.
"Hazardous tsunami waves from this earthquake are possible within the next three hours," the NWS Pacific Tsunami Warning Center said.
New Caledonia is located in a seismologically active zone and regularly suffers from powerful earthquakes.