Japan has offered Indonesia Mogami-class frigates and submarines, Admiral Muhammad Ali said on April 11, as the two countries deepen military ties through a new defence pact signed during a high-level Tokyo visit to Jakarta.
Ali said the offer was conveyed during a recent meeting between Japanese Defence Minister Shinjiro Koizumi and Indonesian Defence Minister Sjafrie Sjamsoeddin, and that the proposals are still being discussed and reviewed by Indonesia’s Defence Ministry. The final decision, he said, will be made in Jakarta.
The talks come after Koizumi visited Indonesia on May 3 and 4, when he and Sjafrie signed a new Defence Cooperation Arrangement that includes an equipment and technology partnership aimed at strengthening maritime deterrence. Sjafrie described the arrangement as a path to “practical cooperation within Japan’s revised arms transfer framework,” while Koizumi has said Japan needs to “loosen its arms export rules” to expand such ties.
The offer matters because Japan’s updated transfer rules now allow exports of lethal military equipment, including warships and missiles, to partner countries that already have defence technology agreements with Tokyo. Indonesia signed such an agreement with Japan in 2021, creating the legal basis for the latest discussions and giving the two governments a framework they have spent years testing.
Those ties have been visible at sea and in port. At least two Mogami-class frigates have already made calls in Indonesia, with JS Kumano visiting in 2023 and JS Yahagi in 2025. The class has also been shown directly to senior Indonesian officials: in 2025, Sjafrie and Ali boarded JS Kumano during separate visits to Yokosuka, while Ali also boarded JS Narushio, the sixth Oyashio-class boat, and Sjafrie boarded the Taigei-class submarine JS Jingei.
No official statement has been made on the exact type of submarine being proposed, leaving one part of the offer deliberately open. Indonesia has formally expressed interest in a second-hand Oyashio-class submarine, but the Japanese side has not said whether that is the model under discussion or whether another platform is being considered.
The Mogami-class itself has become a frequent fixture in regional defence courting. Japan has been showcasing the design to senior Indonesian military and government officials since at least 2021, when reports of a potential sale began circulating. The class has since gained broader attention, too: Australia selected the upgraded Mogami-class as the preferred platform for its future general-purpose frigate programme in August 2025, and New Zealand is also weighing it alongside the UK’s Type 31 for its future frigate requirement.
For Indonesia, the immediate question is not whether Japan is willing to sell, but what Jakarta wants to buy and under what terms. Ali has made clear the Ministry of Defence will decide, and until that happens, the proposal remains a live but unresolved part of a wider effort to turn a long-running defence relationship into actual hardware.
