Tokyo says Washington has signed on to a Japanese final assembly and inspection line for Raytheon’s AIM-120 AMRAAM, a missile Japan ties to its F-35 fleet. Where it will be built, who will run it and when it opens remain undisclosed.
The United States and Japan have agreed to set up a facility in Japan for final assembly and inspection of Raytheon’s AIM-120 air-to-air missile, Japanese Defense Minister Shinjiro Koizumi said Wednesday in the Philippines.
Koizumi announced the deal at a news conference in Cebu after talks with U.S. Defense Secretary Pete Hegseth. According to Japan’s Ministry of Defense, the two met for about 30 minutes on Oct. 28 while attending the Association of Southeast Asian Nations Defence Ministers’ Meeting Plus, or ADMM-Plus.
The agreement commits both governments to building the facility. It does not mean production has started. Japan’s announcements did not say who will own or fund the plant, what it will cost, when it will open, how many missiles it will produce or which version of the AIM-120 it will handle.
“This is a groundbreaking agreement that will not only ensure the acquisition of equipment needed by both Japan and the United States, but will also strengthen Japan’s defense industry base,” Koizumi said, according to a translation of his remarks.
He added that Japan would lift the Japan-U.S. alliance to new heights through actions, not just words, according to the ministry’s Japanese-language transcript.
What a Japanese AMRAAM Line Would Do
The AIM-120, formally the Advanced Medium-Range Air-to-Air Missile, or AMRAAM, is built by Raytheon, an RTX business. Raytheon describes it as a missile for all-weather engagements beyond visual range. It uses inertial navigation and midcourse updates, then switches to its own onboard radar to find its target.
Japan describes the planned site as a final assembly and inspection facility. The ministry’s English summary uses the industry abbreviation FACO, for final assembly and checkout. In practice, that means the last stage of building the missile and testing it before it is accepted.
Janes reported that Koizumi did not announce where the facility will be located.
At a second briefing Thursday, Koizumi again described the agreement and linked the missile to Japan’s F-35 fighters. He gave no date for first production or first delivery.
Japan’s F-35 Fleet
Raytheon says the newest version of the AMRAAM is operational on all F-35 variants. The missile is also fired from the ground as the baseline weapon of the NASAMS air defense system.
Lockheed Martin lists Japan’s F-35 program of record at 147 aircraft: 105 conventional takeoff and landing F-35As and up to 42 short takeoff and vertical landing F-35Bs. Those are planned acquisition totals, not the number of jets now in service.
Japan already hosts one of the F-35 program’s three final assembly and checkout sites. Lockheed Martin says the Nagoya facility, run in partnership with Japanese industry, assembles F-35As for the Japan Air Self-Defense Force, while Japan’s F-35Bs are built in Fort Worth, Texas. That F-35 plant does not indicate where the missile facility will go.
Mitsubishi Electric’s Role Remains Unconfirmed
The planned line grows out of feasibility work by Raytheon and Mitsubishi Electric Corp. At the fourth Japan-U.S. Defense Industrial Cooperation, Acquisition, and Sustainment meeting, known as DICAS, on April 14, officials named circuit card assembly as part of the co-production work and kept discussing a possible final assembly site in Japan.
Two weeks later, Mitsubishi Electric said it was discussing possible participation with industry partners, including Raytheon. The company said that work could cover circuit card assembly and possibly final assembly and checkout in Japan. It said its AMRAAM feasibility studies followed Japanese defense ministry contracts in 2024 and 2025.
Mitsubishi Electric has not been publicly confirmed as the facility’s operator. The records released so far do not name a company to run the plant.
Pentagon Readout Omits Missile Facility
The U.S. side has said less. Air & Space Forces Magazine reported that the Pentagon’s readout of the meeting welcomed Japan’s efforts to build its defense industrial capacity and pledged continued coordination on critical munitions. According to the magazine, the readout did not mention the AMRAAM facility.
In remarks to Southeast Asian defense ministers in Cebu, Hegseth said the administration’s vision for the Pacific rests on strong, self-reliant nations able to defend their own sovereignty, according to a Pentagon transcript.
RTX referred questions about the agreements to the Defense Department, Breaking Defense reported Thursday. The Pentagon had not answered that outlet’s inquiry by the time its report was published.
SM-3 Interceptor Production Also on the Table
The ministers also agreed to share technical information to allow increased production of the Standard Missile-3 Block IIA ballistic missile interceptor, according to the Japanese ministry summary.
That interceptor is a separate program. Raytheon and Mitsubishi Heavy Industries are among the companies named in a U.S. fiscal 2026 plan to expand SM-3 Block IIA production capacity. Mitsubishi Heavy Industries is a different company from Mitsubishi Electric.
At the April DICAS meeting, officials described steps aimed at roughly quadrupling SM-3 Block IIA production and considering further acceleration. The October agreement did not set a new production number.
From Study to Agreement
The Oct. 28 ministry summary refers to Operation Supercharge, a bilateral initiative Koizumi proposed during talks with Hegseth in Singapore on May 30.
The missile effort itself predates that proposal. At a Security Consultative Committee meeting on July 28, 2024, U.S. and Japanese officials welcomed efforts to pursue co-production opportunities that would expand AMRAAM production capacity. In December 2024, the third DICAS forum approved the procedures and scope of an AMRAAM feasibility study.
Separately, RTX announced on Sept. 28 that Raytheon had won a five-year AMRAAM procurement contract, with two option years, worth up to $20.7 billion. The company said the award follows an agreement announced earlier this year that supports annual production of at least 1,900 missiles. Those figures cover the broader AMRAAM program, not Japan’s planned facility.
RTX says 44 countries field the missile.
Key Takeaways
- The U.S. and Japan agreed Oct. 28 to set up a final assembly and inspection facility in Japan for Raytheon’s AIM-120 AMRAAM.
- The deal is a commitment to build the facility. Its location, operator, cost, schedule and output have not been disclosed.
- Mitsubishi Electric did feasibility work with Raytheon but has not been confirmed as the operator.
- The Pentagon’s readout did not mention the missile facility, and RTX referred questions to the Defense Department.
- The ministers also agreed to share technical data to boost SM-3 Block IIA interceptor production.