The quake was initially reported as being a 7.1, but the US Geological Survey has since revised its magnitude downwards.
The USGS says the quake struck at a depth of 15 kilometres, and was located 20 kilometres east of Taron on New Ireland, at 3:40am PNG Time (1740 UTC).
The Pacific Tsunami Warning Centre said that a Pacific regional tsunami was not expected.
This comes as PNG's Highlands region feels significant ongoing aftershocks from a 7.5 earthquake eleven days ago. At least one hundred people are reported to have been killed as a result of this.