The agency did not mention any tsunami alert.
The quake, located 165 miles west of the uninhabited sub-Antarctic Auckland Islands and southwest of South Island, was recorded at 11:35 p.m., about 6.3 miles below the surface, the geological service said.
The epicenter was 506 miles southwest of the southern city of Dunedin on New Zealand's South Island, the U.S. agency said.
In Dunedin, a police officer said there were no immediate reports of injuries or damage. He was speaking on condition of anonymity due to policy.
The quake was not immediately reported by New Zealand's geological agency, GNS Science. No further details were immediately available.
New Zealand sits astride the colliding Australian and Pacific tectonic plates, and experiences more than 14,000 earthquakes each year.
Some 150 of those quakes are felt by residents, while fewer than 10 do any damage.