A strong earthquake with a preliminary magnitude of 6.8 was recorded off the remote northern coast of Papua New Guinea at a depth of about 8 km (5 miles) on Wednesday, the U.S. Geological Survey said.
The Pacific Tsunami Warning Center in Hawaii said in a statement there was no threat of a widespread tsunami from the quake, although it warned that earthquakes of that size could generate destructive tsunamis within 100 km (60 miles) of the epicentre.
The Australian government's Bureau of Meteorology said there was no tsunami threat to Australia.
There were no immediate reports of damage or injury.
In 1998, part of the northern coast of Papua New Guinea was devastated by a tsunami, generated by a 7.0 quake, that killed around 2,200 people.