Australia–Papua New Guinea Mutual Defence Pact

Australia and Papua New Guinea (PNG) are moving forward with a mutual defence agreement that would commit both nations to come to each other’s aid if either is attacked — similar in spirit to other defence alliances.
The pact, often referred to as the Pukpuk Treaty, is designed to deepen security cooperation between the two neighbours, covering areas like military integration, joint training and expanded interoperability.

September 2025: Leaders agreed on the text of the treaty, but PNG’s cabinet initially failed to sign it due to a lack of quorum. Instead, they signed a communiqué outlining shared intent to finalise the deal.
October 2, 2025: PNG’s cabinet approved the treaty, clearing a key internal hurdle.
October 6, 2025: The two prime ministers formally signed the Papua New Guinea – Australia Mutual Defence Treaty in Canberra. It is set to enter into force once each country completes its domestic ratification processes.

The treaty recognises an armed attack on one as dangerous to both peace and security and commits consultation and action in such an event.
It formalises cooperation while respecting sovereignty and territorial integrity.
Both countries plan to enhance defence cooperation, including expanded joint exercises, training and interoperability.
There are provisions for recruitment pathways that would allow PNG citizens to apply to join the Australian Defence Force and potentially other reciprocal arrangements.

Canberra sees the treaty as helping strengthen regional security and stability in the Pacific amid concerns about growing strategic competition, especially from China.
For PNG, the agreement builds on long-standing defence cooperation with Australia and represents its first formal defence alliance with any country.

The pact elevates the Australia–PNG relationship into a formal security alliance — Australia’s first such alliance in over 70 years and PNG’s first ever.
It reflects shared interests in maintaining peace and security in the region, while balancing respect for national sovereignty and independent foreign policy choices.

Here is trhe official Defence Department release: