A landmark defence treaty between Australia and Papua New Guinea has been approved by PNG's cabinet, sources have told the ABC.

The treaty, known as the Pukpuk treaty, will see the two countries agree to defend each other in the event of a military attack.

The treaty was due to be signed during Prime Minister Anthony Albanese’s trip to PNG last month, but the two countries instead signed a "communique" after PNG's cabinet failed to reach a quorum.

The ABC has been told PNG Prime Minister James Marape will release a statement this afternoon.

The mutual defence treaty will allow Australia to recruit soldiers from PNG and vice versa.

It will also see PNG join the United States and New Zealand as only Australia's third formal military ally. Loading

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