Japan's Defence Build-Up Hits US Missile Delays and Parts Shortages

Japan contracted to buy up to 400 U.S. Tomahawk cruise missiles for delivery during fiscal 2025 to fiscal 2027, and U.S. Defense Secretary Pete Hegseth reportedly told Defense Minister Shinjiro Koizumi in May 2026 that deliveries could slip by up to two years, according to SCMP and The Japan Times. The same SCMP report, headlined as a build-up hit by US missile delays and domestic parts shortages, covers U.S. stockpile pressure after operations against Iran, undelivered U.S. orders, and domestic parts shortages that affect Japanese equipment availability.

The facts

Japan's Defence Buildup Program covers fiscal 2023 to fiscal 2027 and requires a very large cumulative expenditure, according to the Ministry of Defense reference material. The 2022 Defence Build-Up Programme sets a 2027 objective for Japan to assume primary responsibility for countering an invasion and includes counterstrike capabilities by 2032, as described in a European Parliament briefing777941_EN.pdf).

Three separate pressures are documented in the research:

• U.S.-side delivery delays. Tomahawk deliveries and other U.S.-sourced munitions face delay because U.S. inventories are being replenished. The Japan Times reported in September 2026 that Washington warned allies, including Japan, of possible delays of up to five years in key weapons deliveries.
• A backlog of Foreign Military Sales orders. Japan's Board of Audit reported in January 2026 that a large number of U.S. military-equipment orders, worth billions of dollars, had remained undelivered for years after contract signing, according to SCMP. Other outlets report the value as approximately 1.1 trillion yen ($6.9 billion) (Economic Times). The two figures diverge in the sources.
• Domestic parts and supplier constraints. The Ministry of Defense evaluation, updated 4 November 2026, states that parts shortages, defense-business withdrawals, discontinued production and unexpected defects are lengthening acquisition lead times and preventing some non-mission-capable equipment from being fully restored during the current programme period.

The research does not contain an official U.S. or Japanese procurement notice, contract announcement or audit finding that confirms the Tomahawk delay itself. The delay rests on press reporting, as detailed below.

Tomahawk delivery: what was reported

The Financial Times reported on 23 May 2026 that Hegseth told Koizumi by phone in early May of the delays, according to the Japan Times. Japan's government had signed a contract with the U.S. government for up to 400 Tomahawks between fiscal 2025 and fiscal 2027 (Japan Times). Japan had expected two batches of 200 Tomahawks by April 2028, and the delay could push that back by up to two years under a $2.35 billion deal finalized in 2024, according to Antiwar.com.

Reporting differs on the status. Military Watch Magazine describes an indefinite suspension, while the FT-based reports describe a delay of up to two years, not a formal suspension. In March 2026, Koizumi had said that delivery of Tomahawks to the Maritime Self-Defense Force had begun, per the Japan Times.

The cause cited is stockpile depletion. CSIS estimated in April that the U.S. military fired more than 1,000, about 30%, of its stockpile of about 3,100 Tomahawks in Iran (Japan Times). On the supply side, RTX entered framework agreements with the Department of War in 2026 covering Tomahawk, AMRAAM, SM-3 IB, SM-3 IIA and SM-6, with planned annual Tomahawk output above 1,000, according to a company announcement carried by Barchart. An August 2026 analysis cited by the Indo-Pacific Studies Center assessed Tomahawk lead times at up to 47 months.

The weapon's role in Japan's planning is stated directly: according to Minemura, quoted by Taiwan News, the Tomahawk is the centrepiece of the counterstrike capability Japan is building.

Domestic production and component dependence

License production in Japan does not remove exposure to U.S. suppliers. Mitsubishi Heavy Industries manufactures PAC-3 MSE missiles under license from Lockheed Martin, but the guidance seekers depend on Boeing supplies, according to Hudson Institute. Reuters reported in July 2024 that U.S. plans to raise Patriot production in Japan were delayed by a shortage of a crucial Boeing-made component, and that MHI then produced around 30 PAC-3 missiles annually and could raise that to around 60 (Kyiv Independent, relaying Reuters). That figure is two years old and is not a current output measurement.

On the U.S. side, Lockheed Martin said it delivered 620 PAC-3 MSE interceptors in 2025, and the deal with the Department of War aims to raise annual capacity from approximately 600 to 2,000 in a seven-year agreement, per the company release and the Lockheed Martin feature. The Defense Post reported that the increase depends on additional fiscal 2026 congressional funding that had not been approved at the time of writing.

A planned AMRAAM assembly facility in Japan faces upstream limits: subcontractor component shortages and long lead times for solid rocket motors have already slowed AMRAAM production, according to SOFREP.

Equipment availability and the supplier base

The Ministry of Defense said operational availability has improved overall but remains affected for some equipment by supply-chain risks, including business withdrawals and disruptions linked to the international environment (MOD evaluation). Its budget materials state that it is securing funding for spare parts and maintenance to address equipment that is not operationally available because of parts shortages (MOD budget briefing).

SCMP reported, citing a security specialist, that only a minority of the Kawasaki P-1 maritime-patrol fleet is estimated to be mission-capable, attributed to spare-parts shortages. The same report lists longer-term component risks for Aegis upgrades, F-15 modernization, MQ-9 maintenance and E-2C Hawkeye aircraft (SCMP). A Japanese official, quoted by SCMP and not independently verified, said the Maritime Self-Defense Force is having to cannibalise parts from other aircraft.

Analysis published by the Hudson Institute and the Japan Times identifies structural factors behind the supplier risk: unstable procurement cycles, small orders, supplier exits, skilled-worker attrition and production-line shutdowns, which make capacity difficult to restore quickly.

Budget scale and spending series

Spending is rising, and the documented constraint concerns delivery and supply rather than appropriations. Ministry of Defense data list total programme-related budgets for fiscal 2023, 2024 and 2025, including initial and supplementary budgets, showing a rise from fiscal 2023 to fiscal 2024 and a decline in fiscal 2025 (MOD budget document).

Tokyo is drafting a new five-year Defence Buildup Program under Prime Minister Sanae Takaichi, who is also revising the National Security Strategy and National Defence Strategy, according to SCMP.

Economic-security and EU cooperation context

At the EU–Japan Defence Industry Dialogue on 17 April 2026, both sides stated that reinforcing defence supply-chain resilience was a shared objective. The statement does not mention U.S. missile-delivery delays, affected programmes or contract values.

What is not known yet

• Whether the Tomahawk deliveries are delayed by up to two years or indefinitely suspended: the sources diverge, and no official U.S. or Japanese notice was retrieved.
• The revised Japanese delivery timetable, any named U.S. supplier tied to the delay, and any quantified financial impact are not available in the sources.
• The current output of Japanese licensed PAC-3 production: the only figure retrieved dates from 2024.
• Reports on the value of the Board of Audit backlog differ across sources, and the sources do not establish how the figures reconcile.
• Whether the U.S. framework agreements will raise output enough to ease allied delivery queues depends on funding approvals not yet confirmed in the research.

Timeline

• July 2024: Reuters reports a Boeing component shortage delaying Patriot production plans in Japan (Japan Times).
• January 2026: Japan's Board of Audit reports undelivered U.S. orders (SCMP).
• March 2026: Koizumi says Tomahawk delivery to the Maritime Self-Defense Force has begun (Japan Times).
• May 2026: Hegseth reportedly informs Koizumi of Tomahawk delays; the FT reports it on 23 May (Japan Times).
• September 2026: The U.S. warns allies of delays of up to five years in key weapons deliveries (Japan Times).
• 4 November 2026: The Ministry of Defense updates its evaluation citing parts shortages and supplier withdrawals (MOD).

Evidence

— InekIA Editorial Team