New Zealand and Japan’s evolving security ties
As talk of New Zealand purchasing a Japanese frigate continues, Australia-based academic Ryosuke Hanada looks at what is driving deepening security cooperation between the two countries, and how far such ties are likely to grow.
A Japanese Mogami-class frigate
Recent discussions surrounding New Zealand’s potential acquisition of Japan’s Mogami-class frigate (FFM) mark a new stage in the two countries’ already evolving defence relationship. In October 2025, during a meeting with former Japanese defence minister Gen Nakatani, Royal New Zealand Navy (RNZN) Chief Rear Admiral Garin Golding conveyed Wellington’s interest in the vessel, signalling an intent to explore Japan’s advanced naval technologies as replacements for New Zealand’s two ageing Anzac-class frigates. The following month, in November 2025, defence ministers Shinjiro Koizumi and Judith Collins reaffirmed their commitment to maintain close communication on the potential frigate deal and to advance negotiations on the Acquisition and Cross-Servicing Agreement (ACSA) and the Information Security Agreement (ISA) as foundational agreements to smoothen their defence partnerships.
These latest developments build on a decade of incremental cooperation, beginning with the Joint Statement on Strategic Cooperative Partnership (2013) and the Statement of Intent on Closer Defence Co-operation (2023). Over this period, Japan and New Zealand have steadily expanded their practical engagement through bilateral and multilateral exercises, such as Exercise KAKADU 2024 and joint maritime patrols with the United States, highlighting the growing depth of their security collaboration across the Indo-Pacific.
The fleet commanders conference of exercise Kakadu 2024
This deepening cooperation coincides with New Zealand’s broader reorientation in defence policy. As Defence Minister Collins declared at the 2025 Shangri-La Dialogue, “distance is no longer the defence it once was.” This recognition of strategic vulnerability has been accompanied by policy changes emphasising regional engagement and interoperability. Wellington has quietly joined the US-led initiative to expand the Indo-Pacific defence-industrial base, signalling a willingness to participate in defence production networks. RNZN HMNZS Aotearoa sailed through the Taiwan Strait with Japan Maritime Self-Defence Force destroyer JS Sazanami and the Australian’s HMAS Sydney on 25 September 2024. Collins’s openness to increased allied warship visits and joint training with traditional and emerging partners –including Japan, Singapore, and the United Kingdom – illustrates a clear move from strategic restraint toward active participation in a networked regional security order.
Defence Minister Judith Colins speaking at the 2024 Shangri-La Dialogue in Singapore
Putting such developments in the broader picture, the accelerating Japan–Australia defence partnership offers an enabling framework for Japan–New Zealand cooperation. By aligning its procurement and operational planning with its Australian ally, as outlined in the 2025 Defence Capability Plan (DCP), New Zealand plans to enhance interoperability and gain access to shared technology and supply chains with Australia. The Joint Statement on Closer Defence Relations (2024) already commits both Canberra and Wellington to “effective defence industry collaboration,” encouraging the removal of barriers to joint capability development. The closer New Zealand-Australia defence ties create synergy between the two bilateral relations by integrating the New Zealand-Japan cooperation into the Japan–Australia defence ecosystem as both Australia and New Zealand operate 1990s-era Anzac-class frigates and Australia has already decided to acquire the Mogami-class frigate.
As researcher at the Asia Pacific Initiative Rintaro Inoue observes, Japan brings advanced expertise in integrated air and missile defence (IAMD) and naval shipbuilding, while Australia excels in cybersecurity and logistics – complementary strengths that can produce a resilient regional defence posture. These complementarities not only reinforce the Japan–Australia relationship but also generate potential spill-over benefits for New Zealand. That said, there are potential limits to how far Japan–New Zealand defence cooperation can advance. First, the 2025 DCP allocates approximately NZD 12 billion (around USD 7 billion) over the next four years, roughly one-twelfth of Australia’s annual defence expenditure, illustrating the disparity in fiscal capacity.
A Japanese P-1 surveillance plane used for surveillance and to patrol over the sea
Corey Wallace, an associate professor at Kanagawa University, points out that Japan’s previous offer to sell the C-2 transport and P-1 surveillance aircraft to New Zealand proved unviable because it exceeded Wellington’s financial and personnel capacity. The upgraded Mogami-class frigate itself costs about USD 690 million per vessel, while Australia’s procurement of 11 frigates under a 10 billion AUD (USD 6.4 billion) programme highlights the scale of investment required.
A more fundamental challenge lies in the evolving structure of regional deterrence. The Indo-Pacific security landscape is increasingly organised around US-centred minilateral frameworks such as the Trilateral Security Dialogue (TSD) linking Australia, Japan, and the United States, the Camp David Trilateral connecting the United States, Japan, and South Korea, and the emerging “Squad” configuration among Australia, Japan, the United States, and the Philippines. These arrangements seek to strengthen deterrence in the East China Sea, the South China Sea, and with clear reference to ‘the Taiwan Strait’ through integrated operations and coordinated strategic messaging. Also, the United States under President Donald Trump builds technological and resource arrangements with its allies to keep its advantage against China.
Australian, Japanese and US commanders pose for a photo following Exercise Bushido Guardian 25, a trilateral exercise between the RAAF, the Japan Air Self-Defense Force and the United States Air Force focused on enhancing interoperability through air combat training
While New Zealand supports the principles of a free and open Indo-Pacific and has endorsed certain US-led initiatives, it remains cautious about being drawn too closely into alliance-based deterrence structures. Wellington’s balancing act – between engaging in US-led collective security and not overly provoking China – will ultimately shape the scope and depth of its partnership with Tokyo.
For Japan, cooperation with New Zealand fundamentally carries diplomatic and normative significance in the Indo-Pacific region, particularly the Pacific Islands, as it underscores inclusivity and shared responsibility among the like-minded nations to secure the rules-based order. That said, the greater the pressure exerted by China in the Taiwan Strait or the East and South China Seas, the more Japan's diplomatic and defence resources will inevitably be allocated to areas and partners anticipating higher-intensity scenarios. This presents an unavoidable issue when considering future Japan-New Zealand cooperation, particularly given that Japan-New Zealand is one of the new “spokes” centred on Australia, and that Japan and Australia themselves form a robust security partnership centred on the United States.
New Zealand Prime Minister Christopher Luxon and former Japanese Prime Minister Fumio Kishida announced an informal security agreement following a summit in 2024
To put it straightforwardly, advancing Japan-New Zealand security cooperation must not create vulnerabilities; rather, it should generate force multipliers for existing security cooperation.
If New Zealand is seriously aiming to acquire the Mogami FFM and, as outlined in the DCP, seeks to obtain equipment as similar as possible to Australia's to enhance interoperability, then it should coordinate with Japan and Australia to develop a plan enabling the RNZN to acquire one vessel following the delivery of the first three to Australia (early to mid-2030s). While construction in Australia is scheduled to commence in 2031, given the uncertainty surrounding labour skills and costs, New Zealand should declare early its intention to acquire one FFM built in Japan, following the delivery to Australia. This would enable personnel training to commence promptly, including boarding RNZN officer on the first Mogami-class FFM operated by Royal Australian Navy possibly in 2029-2030. This approach mirrors the method Australia employed with the USS Virginia-class under the AUKUS initiative.
New Zealand and Japan share multiple multilateral and regional cooperation frameworks where they can promote inclusive and altruistic cooperation. The Comprehensive and Progressive Trans-Pacific Partnership (CPTPP), of which New Zealand is the depository and Japan the largest economy, will be more crucial in protecting a free and rules-based economy. While its purpose and actual actions are yet to become sufficiently clear, one minilateral defence consultation mechanism, the Indo-Pacific Four (IP-4) alongside NATO, can provide venues for New Zealand and Japan to explore concrete areas of taking collective action to reaffirm their common strategic direction in emerging and disruptive technologies, defence industries, addressing disinformation, as well as the space and maritime domains.
About the author
Ryosuke Hanada is a PhD candidate at Macquarie University, working on international security, Japan’s foreign policy and the Indo-Pacific/Pacific Islands. He has been a research fellow at the Japan Institute of International Affairs (JIIA). In October 2025, he was a short-term visiting fellow at the Centre for Strategic Studies, Te Herenga Waka–Victoria University of Wellington.
The Foundation's Asia in Focus initiative publishes expert insights and analysis on issues across Asia, as well as New Zealand’s evolving relationship with the region.
