"The Ministry of Civil Defence & Emergency Management has assessed the information with the assistance of scientific advisors. Based on current information, the initial assessment is that the earthquake is unlikely to have caused a tsunami that will pose a threat to New Zealand."
The Pacific Tsunami Warning Centre said the quake struck southeast of the Loyalty Islands at a depth of 10km at 5.18pm New Zealand Time.
The Pacific Tsunami Warning Centre said hazardous tsunami waves were possible for some Pacific coastlines.
Waves of up to 3m were possible in New Caledonia and Vanuatu. Waves of up 1m were possible in Fiji. And waves up to 300mm were possible in other Pacific areas, including New Zealand.
However a just-released alert says the tsunami threat has now largely passed.
Residents of New Caledonia received text messages directing them to go to refuges immediately.
But people in New Caledonia and nearby Vanuatu said they did not feel the quake, and tsunami warning sirens were not immediately activated in Vanuatu.
There were no immediate reports of damae from the quake.
The Loyalty Islands are part of New Caledonia, found to the northwest of New Zealand.
