On 6 October 2025, Australia and Papua New Guinea (PNG) signed the landmark Papua New Guinea-Australia Mutual Defence Treaty, also known as the Pukpuk Treaty. This represents Australia’s first alliance in 74 years and PNG’s first with any country. It joins the 2 countries in a pact of mutual defence and entails major commitments from both sides.

The treaty underscores recent developments in Australia-PNG defence relations by acknowledging and upgrading previous agreements, and securing a recruitment pathway that will enable PNG citizens to join the Australian Defence Force (ADF). A key component of the treaty is the ‘recruitment of their citizens into each other’s defence forces’ under Article 5(2)(j).

In announcing treaty negotiations in February 2025, Australia’s Deputy Prime Minister and Minister for Defence, Richard Marles, stated that the arrangement would ‘help our two defence forces to work much more closely together’ and enable them ‘to walk down a pathway of increasing integration and increasing interoperability’.

The treaty was referred to the Joint Standing Committee on Treaties on 25 November 2025 for its consideration.

Australia as ‘security partner of choice’

PNG Prime Minister, James Marape, has stated that the treaty was borne ‘out of geography, history, and the enduring reality of our shared neighbourhood’. As the world’s major powers compete for greater influence in the region, experts have highlighted that ‘Pacific Island countries do not want to become pawns in this competition’, and the region’s leaders have ‘vowed to pursue greater security cooperation amongst themselves and with partner states’.

PNG is considered to be ‘one of the strongest proponents for maintaining a Pacific-led security architecture’ and previously bolstered security ties with Australia through a bilateral security agreement in December 2023 and a joint initiative to rebuild PNG’s Lombrum naval base (HMPNGS Tarangau) on Manus Island, which opened in August 2025. Australia invested $500 million to upgrade the base, which has a significant wartime history.

Key treaty provisions

Mutual defence

A core principle of the treaty is its status as a ‘mutual defence Alliance, which recognises that an armed attack on Australia or Papua New Guinea would be a danger to the peace and security of both countries’. Articles 4(2) and 4(3) establish:

(2) In the event of a security-related development that threatens the sovereignty, peace or stability of either Party, the Parties shall consult at the request of either Party and consider whether any measures should be taken in relation to the threat.

(3) Each Party recognises that an armed attack on either of the Parties within the Pacific would be dangerous to each other's peace and security and the security of the Pacific, and declares that it would act to meet the common danger, in accordance with its constitutional processes.

These measures build on the 1987 Joint Declaration of Principles guiding relations between Australia and PNG, including their agreement to consult on ‘matters affecting their common security interests’ or in ‘the event of an external armed threat’ to either country.

Access to agreed facilities and areas

Article 7 details ‘unimpeded access to and use of Agreed (PNG) Facilities and Areas’ to the Australian Defence Organisation, its personnel and others as mutually determined – a measure that can benefit both sides and strengthen Australia’s position in the region.

In April 2023, Foreign Minister Penny Wong stated that Australia would ‘contribute to the regional balance of power that keeps the peace by shaping the region we want’ and where ‘all countries benefit from a strategic equilibrium’. Strategic contest is challenging this equilibrium.

In 2024, the Guardian mapped the network of security deals in the Pacific, including more than 60 agreements and initiatives that support policing and defence. It found that China supports ‘nearly half a dozen’ policing initiatives in the region. In defence, the US will invest more than US$864 million on infrastructure and military training in PNG over 10 years under a 2023 agreement that gives the US military unimpeded access to PNG’s bases.

Military recruitment

A subject of recent debate, Pacific recruitment for the ADF is now being developed as a policy. On 20 October 2025, at the 31st Australia-Papua New Guinea Ministerial Forum, talks included progressing ‘the PNG-Australia Alliance through the establishment of a recruitment pathway that will enable PNG citizens to join the Australian Defence Force’.

In 2024, the Albanese Government flagged its plans to expand ADF recruitment to the Pacific. The Australian Strategic Policy Institute (ASPI) explored options in its April 2024 report: 

1. Direct recruiting from the Pacific region into the ADF 
2. Closer integration and operation between existing Australian and PIC [Pacific Island countries] forces 
3. A broader partnership model drawing on lessons from the US’s ‘compacts of free association’ and from the UK’s defence recruitment initiatives. 

Most Pacific Island Country officials favoured a ‘regional Pacific Regiment–style option’ (p. 17). On the idea of a combined ‘Pacific battalion’, ASPI found:

Arguably, more than any other option, this model provides the opportunity for Pacific islanders to be involved in military and security roles most relevant to them and to their own major security challenges. The skills exchange would benefit Australian personnel just as much as PIC personnel, as the vast experience across the region will be able to be shared to build regional expertise (p. 13). 

In May 2025, ANU National Security College expert associate, Jennifer Parker, proposed a hybrid system where Pacific soldiers operate in their own units but under an ADF banner. Noting the potential negative implications of taking people away from their home country, Parker advised ‘recruiting units as opposed to individuals with a policy that if they serve in Australia, they return home after service’. Ex-Gurkha officer and chief executive of a PALM scheme employer, Ross Thompson, highlighted the need to balance offers of ‘fast-tracked citizenship’ against the return of skills to a recruit’s home country. Recruiting from PNG for the ADF could strengthen regional security and benefit PNG’s future capability, according to Thompson.

A bilateral taskforce is overseeing the recruitment process, which will start in January 2026.