A tsunami warning has been issued for NZ's coastal areas after a 7.1 magnitude earthquake in the North Island.

Civil Defence says people near the coast who felt a long or strong quake should move immediately to the nearest high ground, out of all tsunami evacuation zones or as far inland as possible.

The National Emergency Management Agency and GNS Science have assessed the quake created a tsunami that could cause coastal flooding on the East Coast of the North Island from Cape Runaway to Tolaga Bay.

The first waves were detected on East Cape at about 3.15am.

Nearly 60,000 people have reported feeling the quake on GeoNet.

It struck at 2.27am, 105km east of Te Araroa at a depth of 90km.

GeoNet has described the quake as being severe.