A magnitude 6.8 quake struck south southeast of Raoul Island in the South Pacific Kermadec Islands chain, the U.S. Geological Survey reported.
The quake struck 180 km south southeast of Raoul at a depth of 10 km, USGS said.
There were no immediate reports of any casualties.
The Kermadec Islands constitute a part of New Zealand and are situated some 1000 kilometres northeast of the country. The islands are uninhabited with the exception of Raoul Island.
New Zealand is located in a seismically active zone known as the Ring of Fire and regularly suffers from powerful earthquakes.