A 6.5-magnitude earthquake struck off Papua New Guinea on Monday, officials said, but no Pacific-wide tsunami warning was issued.

The tremor hit at a depth of 28 kilometres (17 miles) near sparsely populated New Britain Island, 450 kilometres northeast of the capital Port Moresby, the United States Geological Survey said.

The Hawaii-based Pacific Tsunami Warning Center ruled out a widespread tsunami.

"Based on all available data, a destructive Pacific-wide tsunami is not expected," it said.

New Britain, the largest island of the Bismarck Archipelago, is east of mainland New Guinea and has a population of around 500,000 people.