Japan to Cooperate With United States to Develop New Destroyers With Aegis Combat System

Japan’s Acquisition, Technology & Logistics Agency will cooperate with the US Department of the Navy to develop new missile destroyers with the Aegis Combat System.

This is according to the official list of contracts signed by the agency in May 2025.

According to the published information, the contract was signed with the US Department of the Navy to conduct a technical study to replace the Congo-class destroyers.

Since the contract for the development of a new type of ship is at the initial stage, the Ministry of Defense of Japan is currently signing contracts for the priority work on the formation of the terms of reference.

It should be noted that this cooperation in the development of new Japanese destroyers with the Aegis Combat System is linked to the agreement on Joint Missile Defense Agency (MDA), through which the US side will customize the system for Japanese ships.

As of today, the Japanese Maritime Self-Defense Forces are using four Congo-class missile destroyers built between 1988 and 1998: ‘Congo’ (DDG-173), ‘Kirishima’ (DDG-174), ‘Myōkō’ (DDG-175), ‘Chokai’ (DDG-176).

The ships have a standard displacement of 7,250 tons and a gross tonnage of up to 9,500 tons with a length of 161 meters, a width of 21 meters and a draft of 6.2 meters. They are equipped with a COGAG propulsion system, which includes four General Electric LM2500 gas turbines with a total capacity of 100,000 horsepower, providing a maximum speed of up to 30 knots (56 km/h) and a range of approximately 4,500 nautical miles at 20 knots. The destroyer’s crew consists of about 300 people, and its autonomy is up to 30 days.

The Congo-class destroyers are armed with 90 Mk 41 VLS vertical launchers for SM-2MR Block IIIA/B, SM-3 Block IA (for missile defense), SM-6 and ASROC anti-submarine missiles, as well as eight Harpoon anti-ship missiles in two four-tube launchers.

For close defense, there are two Phalanx CIWS 20 mm anti-aircraft artillery systems and two Mk-46 three-torpedo anti-submarine warfare vehicles.

The Aegis Baseline 3.5 battle management system (upgraded to Baseline 5 on later ships) with AN/SPY-1D radar provides detection and tracking of up to 100 targets simultaneously at a distance of up to 400 km, and the AN/SQQ-89 sonar system with SQS-53B/C sonar and SQR-19 system for towed antenna allows for effective submarine detection.

Additionally, the ships are equipped with NOLQ-2 electronic warfare systems and four Mk-36 SRBOC jamming launchers.

The new destroyers are planned to replace all four ships and at the same time complement the existing Maya and Atago missile destroyers, as well as the new ASEV missile defense destroyers, which are designed to strengthen the country’s missile defense by abandoning the Aegis Ashore system.

Earlier, Militarnyi reported that the US State Department had approved the possible sale of Standard Missile-6 (SM-6) anti-aircraft ship missiles to Japan.