Indonesia eyes Japan's Upgraded Mogami-class frigates during trilateral defense talks with Australia.

Japan and Indonesia held preliminary trilateral talks with Australia on August 26, 2026, during which Jakarta renewed its strategic interest in acquiring eight units of Japan's Upgraded Mogami-class frigate (New FFM). The prospective deal revives a ¥300 billion procurement framework first discussed in 2021, shifting focus to an enlarged 6,200-ton design equipped with expanded strike capacity. This renewed push allows the Indonesian Navy (TNI AL) to capitalize on Australia's SEA 3000 export precedent while working to resolve parallel negotiations over second-hand Asagiri-class destroyers.

The Upgraded Mogami-class frigate increases overall length to 142 meters and full-load displacement to 6,200 tonnes, incorporating a doubled 32-cell Mk 41 Vertical Launch System alongside specialized mine-warfare and anti-submarine suite options. Operating with an automated 90-person crew, an eight-ship fleet would reduce overall personnel requirements compared to traditional warship design alternatives while offering local construction at PT PAL in Surabaya.

Related topic: Japan to begin talks to export Mogami frigates to New Zealand following Australian selection

The earlier Mogami-class talks between Japan and Indonesia envisaged four frigates built in Japan and four constructed by PT PAL in Surabaya under a package valued at roughly ¥300 billion. (Picture source: Japanese MoD)

On August 26, 2026, the Japan Times announced that Indonesia renewed its interest in acquiring Japan's Upgraded Mogami-class frigate, or New FFM, during the first trilateral defense talks between Japan, Indonesia and Australia, bringing back an eight-ship procurement talk first pursued in 2021 with the original Mogami-class, but now involving a frigate that carries twice as many Mk 41 cells and has become the basis of an 11-ship Australian program. Jakarta has not yet moved to contract negotiations because the government is expected to settle its parallel discussions over second-hand Asagiri-class destroyers first. Those working-level Asagiri talks began in June 2026, one month after Indonesia and Japan signed a Defence Cooperation Arrangement on May 4 covering equipment, technology and maritime cooperation.

The Mogami proposal itself goes back to 2021, when Japan planned to supply four ships from Japanese yards and have four more built by PT PAL in Surabaya under a package valued at roughly ¥300 billion. Financing became one of the obstacles because Jakarta's rules required 10-20% upfront funding, which on ¥300 billion equated to ¥30-60 billion before the remainder of the acquisition could be distributed across later budgets. The proposal lost momentum, but Japanese engagement continued through JS Kumano's visit to Indonesia in 2023, JS Yahagi's visit in 2025, and separate 2025 visits by Defence Minister Sjafrie Sjamsoeddin and TNI AL Chief of Staff Adm. Muhammad Ali aboard Kumano at Yokosuka. In April 2026, Adm. Ali had confirmed that Tokyo had again offered the frigate.

Indonesian Ambassador Heri Akhmadi was also pressing for technology transfer and cooperation that would increase Indonesia's access to Japanese production methods and naval systems rather than limit the transaction to imported ships. The acquisition being reconsidered in 2026 is therefore materially different from the one that stalled five years earlier. The original Mogami-class measures 133 m in length, 16.3 m in beam and roughly 4.5 in draught, displaces 3,900 tonnes standard and about 5,500 tonnes at full load. Its CODAG machinery combines one Rolls-Royce MT30 gas turbine with two MAN 12V28/33D STC diesel engines on two shafts, producing roughly 70,000 hp and allowing a maximum speed above 30 knots. The New FFM increases the overall length to 142 m, beam to roughly 17 m, standard displacement to 4,880 tonnes and full-load displacement to about 6,200 tonnes.

The enlarged hull creates space for a larger missile battery, greater electrical capacity, additional command and sensor equipment, and more reserve margins for later modifications. Japan subsequently reduced the original Mogami program from 22 to 12 ships after the Acquisition, Technology and Logistics Agency (ATLA) began the transition toward the New FFM configuration in 2023. Japan intends to acquire roughly 12 New FFMs between FY2024 and FY2028, which implies an average procurement rate of two to three ships annually. The largest quantifiable combat change is the vertical launching system (VLS). The baseline Mogami carries 16 Mk 41 VLS cells, while the New FFM carries 32 strike-length Mk 41 cells forward of the bridge, doubling the cell count.

Japanese New FFMs are intended to use the launcher for Type 23 surface-to-air missiles and Type 07 vertical-launch anti-submarine rockets, while the Australian variant will use RIM-162 ESSM and demonstrates that the launcher can support a customer-specific load. If every cell were assigned to quad-packed ESSM, 32 cells could theoretically hold 128 missiles, compared with 64 in a Mogami-class, although a realistic wartime load would reserve cells for several weapon types rather than dedicate the entire magazine to one interceptor. The Upgraded Mogami also retains a 127 mm Mk 45 naval gun, SeaRAM close-in defense, 324 mm lightweight torpedo armament, and helicopter facilities, while Japan intends to integrate an improved Type 12 anti-ship missile. The baseline Mogami carries eight Type 17 SSM-2 anti-ship missiles in two quadruple launchers, with an estimated engagement range of 200 to 250 km, compared with roughly 150 to 200 km for the Type 90 missile it replaced.

The Type 07 VL-ASROC provides a separate anti-submarine attack option beyond 30 km before delivering its lightweight torpedo into the target area. The SeaRAM adds an 11-round terminal-defense magazine with an engagement envelope of roughly 9 to 10 km, while the 127 mm Mk 45 can engage conventional surface or shore targets at roughly 24 km with standard ammunition. Anti-submarine and mine warfare are equally important because Indonesia operates across narrow straits, deep-water basins and approaches where submarines can exploit complex acoustic conditions. The baseline Mogami combines the OPY-2 X-band AESA multifunction radar, OAX-3 electro-optical and infrared system, OQQ-25 variable-depth and towed-array sonar, OQQ-11 mine-hunting sonar, OYQ-1 combat management system and NOLQ-3E electronic warfare system.

The OQQ-25 allows the frigate to vary sonar depth instead of relying only on a fixed hull installation, which is particularly relevant where thermoclines can mask submarine contacts. The towed array provides a longer acoustic aperture for passive detection, while an embarked SH-60 helicopter can move the search beyond the ship's immediate sonar horizon using its own sensors and lightweight torpedoes. Once a contact is localized, the ship can use Type 07 VL-ASROC at distances above 30 km or its own 324 mm torpedo tubes at shorter range. The New FFM retains that anti-submarine architecture while adopting an improved radar derived from the OPY-2 and providing greater power and space margins for later sensor changes. The mine warfare package further differentiates the design from many frigates of similar displacement.

The Mogami-class can carry a UUV, USV, mine-disposal craft, mine-hunting sonar and simplified mine-laying equipment, allowing the ship to survey routes, investigate suspected minefields and support mine-clearance operations while still carrying its normal anti-submarine, anti-surface and air defense weapons. For Indonesia, that combination has direct geographic relevance because the loss or temporary closure of a narrow strait, naval-base approach or commercial channel can affect fleet movement and national shipping without requiring an enemy to defeat the Indonesian surface fleet in conventional combat. Western frigates in the 5,000-7,000-ton range commonly require 140 to more than 200 sailors, while the Mogami family was structured around roughly 90, despite the New FFM's growth to about 6,200 tonnes full load.

The New FFM achieves its reduced complement through centralized machinery control, propulsion monitoring, navigation, damage-control supervision and combat management rather than by simply removing positions from a traditional frigate organization. The Mogami's Advanced Integrated CIC combines navigation, engineering, and tactical functions within a heavily automated control environment, while panoramic displays and centralized monitoring reduce the number of operators required for routine watchstanding. This matters more for Indonesia than it would for a navy replacing one standardized frigate class with another because the Indonesian Navy (TNI AL) is introducing several unrelated ship families simultaneously.

Every additional class creates new requirements for propulsion engineers, radar technicians, sonar operators, missile personnel, electronic warfare specialists, aviation crews, and dockyard workers, so saving 480 to 880 embarked billets across an eight-ship class can influence how many ships are actually crewed and deployable rather than merely reducing salary costs. Like for the Indonesian Air Force, the main procurement risk is therefore not insufficient capability but the accumulation of different naval suppliers. Indonesia is already constructing two Merah Putih frigates derived from the British Arrowhead 140 at PT PAL in Surabaya, and a January 2026 agreement for two additional Arrowhead 140 ships could bring the family to four. It also signed for two Turkish Milgem Istif/I-class frigates with TAIS Shipyards at IDEF 2025.

Another €1.18 billion contract signed in 2024 covers two Italian Thaon di Revel/PPA vessels, while an Italian package announced in 2021 included six FREMM frigates, two modernized Maestrale-class frigates and associated logistics support, although funding continues to constrain implementation. Indonesia is also receiving the former Italian aircraft carrier Giuseppe Garibaldi. The French Naval Group contract for two Scorpène Evolved Full LiB submarines entered into force on July 23, 2025, with construction in Indonesia and technology transfer included, while Jakarta has separately examined second-hand Japanese submarines. If all of the principal surface programs proceeded without offsetting cancellations or reductions, the prospective frigate-sized pipeline could include four Arrowhead 140/Merah Putih ships, two I-class frigates, two PPAs, up to six FREMMs and eight New FFMs.

That equals as many as 22 ships across five major design families before legacy frigates, corvettes and possible Maestrale transfers are counted. Each family brings a separate combination of engines, reduction gears, radar modules, sonar hardware, combat management software, electronic warfare equipment, missiles, torpedoes, data links, training simulators and depot-maintenance procedures. A fleet of 22 new ships can therefore create greater operational output only if Indonesia can simultaneously fund ammunition stocks, spare engines and components, dockyard capacity, software support, crew training and periodic modernization. Otherwise, nominal fleet growth can outpace actual availability. Japan's production record reduces some schedule risk, but an Indonesian order would still have to compete for shipyard capacity.

The JMSDF commissioned JS Nagara, FFM-10, on June 29, 2026, bringing the baseline Mogami fleet to ten operational ships. Nagara was laid down on July 6, 2023, launched on December 19, 2024, and delivered on June 29, 2026, producing a roughly 36-month keel-to-delivery cycle. Japan's FY2025 budget allocated roughly ¥314.8 billion for three New FFMs, equivalent to ¥104.9 billion per ship when divided evenly. That number is substantially higher than the ¥42.9 billion arithmetic average produced by Mitsubishi Heavy Industries' ¥128.6 billion February 16, 2026 contract for New FFM hulls three through five. The gap is important because it shows why hull construction contract values cannot be compared directly with complete acquisition budgets: major sensors, weapons, VLS equipment and other government-furnished systems can appear on separate funding lines.

Mitsubishi Heavy Industries has built 10 of the 12 baseline Mogami hulls at Nagasaki and is moving directly into New FFM production, preserving workforce continuity and reducing the disruption associated with restarting a dormant line. However, those yards must now support Japan's own 12-ship requirement and Australia's first three ships. If Indonesia ordered four Japanese-built frigates before moving construction to PT PAL, delivery would depend on when those hulls could be inserted alongside domestic and Australian production rather than simply applying Nagara's 36-month construction cycle four times. Australia gives Jakarta the clearest indication of what a revised Indonesian agreement could look like because Canberra has already negotiated the industrial and configuration questions that remained unresolved in Indonesia's earlier proposal.

Australia selected the New FFM on August 5, 2025, after considering Germany's MEKO A-200, South Korea's FFX Batch II/III and Spain's Alfa 3000. The program covers 11 frigates for roughly AU$10 billion, with the first three built by Mitsubishi Heavy Industries in Japan and eight at Henderson in Western Australia. That equates to 27% Japanese construction and 73% Australian construction by hull count, compared with the 50-50 four-plus-four division proposed for Indonesia in 2021. First delivery is planned for 2029 and operational service from 2030, five years earlier than the 2034 first-delivery schedule associated with Australia's previous planning baseline. Australia also rejected a simple duplication of the JMSDF weapons fit. Its ships are planned to use Kongsberg Naval Strike Missiles instead of Type 17 anti-ship missiles, Mk 54 lightweight torpedoes, SeaRAM and RIM-162 ESSM in the 32-cell Mk 41 VLS.

That matters for Indonesia because it establishes that the exported frigate can retain the Japanese hull and propulsion architecture while integrating customer-selected weapons. Jakarta could therefore negotiate not only four Japanese-built and four Indonesian-built hulls, but also which missiles occupy the VLS, whether the anti-ship weapon remains Japanese or comes from another supplier, which combat system elements are localized, what software access PT PAL receives, and which maintenance functions are transferred to Surabaya. Australia has already established the basic precedent that New FFM export does not require the foreign customer to adopt the JMSDF configuration unchanged.

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.

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