Australia and Japan signed a historic defense deal on June 18[1] to supply up to 11 Japanese‑built Mogami‑class frigates. The agreement was announced simultaneously in Canberra and Tokyo, highlighting the bilateral nature of the partnership.
The pact is designed to strengthen Australia’s naval capabilities and deepen the defence partnership between the two allies, a priority as both nations confront growing maritime challenges in the Indo‑Pacific region.
The contract’s price is reported at about A$10 billion[3], which converts to roughly U.S. $7 billion[2] at current exchange rates. Some outlets, however, have placed the total cost at A$20 billion[4], illustrating the variance in reporting methods.
Under the terms, Mitsubishi Heavy Industries will construct the first three frigates in Japan[6], while the remaining vessels will be built in Australian shipyards[7]. In total, the two countries will deliver 11 frigates[5], expanding the Royal Australian Navy’s surface‑warfare and anti‑submarine capabilities.
The joint procurement follows a series of defence collaborations, including regular maritime exercises and technology exchanges, that have been building interoperability between the forces. By incorporating an Australian construction phase, the deal also aims to develop local industry and sustain long‑term maintenance capacity.
Analysts note that the agreement aligns with both governments’ strategic emphasis on freedom of navigation and collective security in a region marked by heightened naval activity. The addition of modern frigates will give Australia a more versatile fleet as it seeks to protect sea lanes vital to trade.
The Indo‑Pacific region has become a focal point for naval activity, with major powers expanding fleets and conducting frequent exercises. For Australia, a vast coastline and reliance on sea‑borne trade make a capable navy essential. By acquiring modern frigates, Canberra aims to keep pace with evolving threats, including submarine incursions and surface threats, while maintaining a credible deterrent.
Beyond the ships themselves, the partnership is expected to foster deeper technological cooperation. Joint training programs and maintenance support arrangements are anticipated, allowing Australian crews to operate the vessels alongside Japanese counterparts. This collaborative approach seeks to ensure interoperability and shared readiness, reinforcing the broader security architecture that both governments have been building over recent years.
The contracts were signed after months of negotiations between the Australian Department of Defence and Japan’s Ministry of Defense, finalizing specifications and delivery timelines.
“Australia and Japan signed a historic defense deal on June 18 to supply up to 11 Mogami‑class frigates.”
The deal deepens the strategic bond between Australia and Japan, giving Canberra a modern frigate fleet while expanding Japan’s defence export footprint. By splitting construction between Japan and Australia, the agreement also boosts domestic shipbuilding capability and ensures long‑term logistical support. In the broader Indo‑Pacific context, the partnership enhances collective maritime security and signals a coordinated response to rising naval activity in the region.
