Hegseth and Koizumi agree on new Japanese missile production line

Japan will host a final assembly plant for the AIM-120 AMRAAM air-to-air missile after Defense Minister Shinjiro Koizumi and U.S. Secretary of War Pete Hegseth agreed on Oct. 28 to build the facility as part of joint U.S.-Japanese missile production, Nikkei reported.

The two met for about 30 minutes in Cebu, the Philippines, on the sidelines of an expanded meeting of Southeast Asian defense ministers. The facility, known as a final assembly and check-out plant, or FACO, is where completed components are put together into finished missiles and tested before delivery, Financial News reported, citing the Asahi Shimbun and NHK. Hegseth welcomed Japan’s work to strengthen its defense production base, and the two sides also agreed to expand joint exercises, including live-fire drills.

The ministers also agreed to share technical information to expand production of the SM-3 Block IIA, a ship-launched interceptor that destroys ballistic missiles in space, Nikkei reported. The Japanese side said Hegseth did not press for a specific increase in Japan’s defense budget, and the Defense Ministry said the talks were not held with any particular amount or outcome in mind.

The AMRAAM is a radar-guided missile that fighters fire at enemy aircraft beyond visual range, and it guides itself to the target after launch, so the pilot can turn away or engage another threat. It arms U.S. and allied F-15, F-16, F/A-18, F-22 and F-35 fighters, including the F-35s that Japan is buying, and it also serves as the main interceptor for the ground-based NASAMS air defense system. Raytheon builds the missile in the United States and in February agreed with the U.S. Department of War to raise annual AMRAAM production to at least 1,900.

The plant would take a years-long effort a step further. The United States and Japan first agreed in July 2024 to explore joint production of the AMRAAM and the PAC-3 MSE Patriot interceptor, and Japan’s Acquisition, Technology and Logistics Agency then ran a feasibility study with Mitsubishi Electric and Raytheon. In April, the two governments identified circuit card assembly, the production of the missile’s electronic boards, as part of Japan’s share, with a final assembly plant in Japan raised as a possibility, Mitsubishi Electric said. Japan is also a major AMRAAM customer: in January 2025, the U.S. State Department approved the sale of up to 1,200 AIM-120D-3 and AIM-120C-8 missiles to Japan, valued at an estimated $3.64 billion.

The SM-3 Block IIA has a longer history as a shared program. Raytheon and Mitsubishi Heavy Industries developed it jointly, and it entered full-rate production in 2024. In March, the two governments agreed to quadruple production of the interceptor in Japan, and Japan now pays for a large share of new orders, covering nearly half the immediate funding in a $745 million contract for SM-3 Block IIA missiles awarded this summer.

During the meeting, Koizumi briefed Hegseth on Japan’s plan to revise its three main national security documents by the end of 2026. He said Japan would strengthen what it calls denial defense, the ability to stop an invading force from succeeding, along with deterrence intended to discourage an attack in the first place. The ministers also agreed to step up cooperation against cyberattacks, The Japan Times reported.