Taiwan Security Monitor

Taiwan Arms Sales Backlog, March 2025 Update: New SIPRI Data Sheds Light on Partial Deliveries

By Eric Gomez

The backlog of US arms sales announced but not delivered to Taiwan did not change in March 2025. As shown in Figure 1, the backlog remains $21.54 billion.

New SIPRI Dataset Reveals a Large Delivery in Progress

SIPRI released its annual update to the Arms Transfer Database in March 2025, which brings the data current as of the end of 2024. Tracking the delivery status of arms sales, to Taiwan or any other country, is a very difficult task. SIPRI’s dataset has been a valuable source of information for the Taiwan arms backlog project since its first publication in November 2023.

However, SIPRI’s data is also imperfect. The 2025 edition of the dataset, for instance, categorizes the sale of 11 HIMARS systems to Taiwan as partially delivered, despite the Ministry of National Defense (MND) confirming full delivery in late 2024. SIPRI is also missing two major Taiwan arms sales from its dataset: a plus-up of 18 additional HIMARS and 100 PAC-3 MSE interceptors for the Patriot air and missile defense system. In SIPRI’s defense, confirming the existence of these two arms sales was not easy. Because both cases were modifications to older arms sales, their notifications were published in the Congressional Record instead of the Defense Security Cooperation Agency’s website, which is a much more readily accessible source of information.

For the most part, SIPRI’s 2025 update comports with other information I collected in 2024 about the arms sale backlog, but there was one noteworthy development.

According to SIPRI’s dataset, Taiwan has started receiving components of the Harpoon Coastal Defense System or HCDS, a truck-mounted version of the Harpoon anti-ship missile. In October 2020, Congress received notification of a $2.37 billion sale of 100 HCDS launchers, 400 missiles, and 25 radar trucks. The HCDS case is the second-largest arms sale by dollar value in the backlog. In September 2024, Taiwan’s Liberty Times reported that some HCDS equipment had arrived in Taiwan, but I did not feel confident coding HCDS as partially delivered at that time because the Liberty Times reporting was not well detailed.

Based on SIPRI’s data, I feel confident in changing the HCDS sale to partially delivered. Like the Abrams tank sale, this partial delivery status is expressed by a different color in the Figure 1 pie chart. As a reminder, the dollar value of the Taiwan arms sale backlog will not be reduced until final delivery of the arms sale occurs because trying to estimate a dollar value for partial delivery would be too difficult and likely inaccurate. Partial delivery of arms sales worth more than $1 billion are displayed visually in Figure 1 and noted with yellow text in Table 1.

First New F-16 Rolls Off Delivery Line

The largest arms sale in the backlog, 66 F-16 Block 70/72s valued at $8 billion, also saw a major development in March 2025, as the first aircraft rolled off the assembly line. Delivery of the first F-16 is approximately two years behind schedule. An October 2024 MND report to the Legislative Yuan cited software problems and other development bottlenecks as the main culprit for delays.

Although the first F-16 has now finished assembly, I have elected to not mark this sale as being partially delivered. The October 2024 MND report and March 2025 reports from Taiwan’s Central News Agency and Taipei Times mention that there will be some gap between the new aircraft being produced and their delivery to Taiwan. This probably is because the aircraft will need to undergo some final flight testing and perhaps pilot training in the United States. Until the first F-16 Block 70/72 lands on Taiwan’s territory, I will not consider this sale to be partially delivered.

The Taiwan Security Monitor will continue keeping tabs on the F-16, HCDS, and all other arms sales in the backlog.


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Taiwan Arms Backlog, February 2025 Update: Early Trump Admin Arms Sales and Rumors of a Big Request from Taiwan

By Eric Gomez

There were no new US arms sales to Taiwan announced or delivered between January and February 2025. The backlog remains $21.54 billion.

Figure 1 shows how the backlog is divided among traditional capabilities, asymmetric capabilities, and munitions. Table 1 contains an itemized list of arms sales in the backlog.

Sources: Defense Security Cooperation Agency: Press ReleaseUS Congressional Record; “Major Arms Sales,”; DCSA ReleaseDCSA Major Arms SalesDCSA Press Media TECROSIPRI Arms Transfers Database, Stockholm International Peace Research Institute; US Congressional Record; “Major Arms Sales,” Defense Security Cooperation Agency; “Defense News,” Ministry of National Defense, Republic of China; “Letter from the Ministry of National Defense, Submitting a Written Report on the ‘Implementation Status of US Arms Sales to Taiwan’ for the 2024 Budget Resolution,” Ministry of National Defense, June 12, 2024; and “Excerpt from ‘Ministry of National Defense 2024 Annual Budget Assessment Report’,” Ministry of National Defense, October 2023; and “Information on US Arms Sales to Taiwan,” Ministry of National Defense, October 30, 2024.

Early Trump Arms Sales

February 2025 was a busy month in the world of foreign military sales (FMS) despite none going to Taiwan. The Trump administration notified Congress of nine FMS cases in February. Five of these cases, with a combined value of $10.4 billion, were for Israel.  

In three of the Israel arms sales, the Trump administration bypassed the standard Congressional review period for FMS cases by stating an emergency existed justifying an immediate sale. Normally, Congress would have either 15 or 30 days—depending on the recipient country, Israel’s period is 15 days—to issue a joint resolution of disapproval to block the arms sale. The Trump administration’s invocation of an emergency is legal under the Arms Export Control Act, which governs FMS cases, but drew condemnation from several members of Congress arguing that the administration cut Congress out of politically sensitive sales.

Between inauguration day and the end of February, Middle Eastern countries have been the recipient of eight out of ten FMS cases (Japan and Romania have one sale apiece over the same period). It will be interesting to see if this trend continues. While there appears to be a consensus around reducing US focus on Europe, the administration’s approach to the rest of the world is not settled. Much of the administration’s senior foreign policy team has talked about focusing more on China, but recent arms sales and developments in March 2025 suggest more attention on the Middle East at least in the near term.

Rumors of a Large Taiwan Arms Sale

While there has been no official notification of the next US arms sale to Taiwan, the rumor mill was active in February. A Reuters report citing “sources familiar with the situation” said that Taiwanese and American officials were discussing a large arms sale with a price tag between $7 and $10 billion. The full scope of capabilities under discussion was not mentioned, but the Reuters article references HIMARS munitions and coastal defense cruise missiles. Taiwan is already waiting for delivery of these weapons from earlier arms sales, but both are asymmetric capabilities that would be good acquisitions for Taipei.

The last time the press reported on rumors of a Trump administration arms sale to Taiwan was in November 2024, shortly after the election. The Financial Times reported that Taiwan was thinking about making an overture to the incoming administration with a large weapons purchase. Traditional capabilities like F-35 fighter aircraft, E-2D airborne early warning and control aircraft, and retired Ticonderoga-class cruisers featured heavily in the November 2024 rumors, and the dollar figure was much higher at $15 billion.

With the caveat that none of the above information has been confirmed by either the US or Taiwanese governments, the change between the two reports is interesting. Traditional capabilities factored much more heavily in the earlier report, while the more recent report focused on asymmetric capabilities. Both packages would result in a sizable increase in the Taiwan arms sale backlog, but based on recent delivery timelines the February 2025 capabilities should arrive faster than the November 2024 capabilities.

Hopefully, as these negotiations unfold, Taiwan and the United States will keep moving closer to sales of asymmetric capabilities that are easier for Taiwan to afford and more likely to be delivered quickly. The appeal of traditional capabilities like F-35s or large surface warships is understandable, but given Taiwan’s levels of defense spending and longer delivery timelines buying more traditional capabilities would be an imprudent use of time and money.

Conclusion

February 2025 did not see any changes in the US arms sale backlog to Taiwan, but it did provide a peek into important issues that could impact the backlog. The Trump administration’s early emphasis on the Middle East for new arms sales raises questions about whether the administration’s actions will reflect its “China first” rhetoric. New rumors about a pending US arms sale to Taiwan suggest ongoing tension between Taiwan going all in on asymmetric defense versus securing Trump’s favor via the purchase of high-priced traditional capabilities.


For the full dataset, click below:

Taiwan Arms Sale Backlog, January 2025 Update: F-16 Delays and New Contracts

By Eric Gomez and Joseph O’Connor

The US arms sale backlog to Taiwan is slightly reduced from December 2024 thanks to new research conducted by the Taiwan Security Monitor team. There were no new foreign military sales (FMS) cases announced in January 2025 or announcements of full deliveries. However, we have removed a $332 million sale of 30mm ammunition from the backlog, which results in a new total backlog value of $21.54 billion.

Figure 1 shows how the arms sale backlog is divided across weapons categories. The 30mm ammunition FMS case was coded as Munitions in the dataset. The different color for the Abrams sale, coded as a Traditional weapon system, indicates that deliveries of the sale have started but have not finished.

The two other noteworthy developments in the arms backlog this month are new information about delivery delays for F-16 Block 70/72s and contract announcements for air defense systems that were notified to Congress in the last few months of the Biden administration.

Sources: Defense Security Cooperation Agency: Press ReleaseUS Congressional Record; “Major Arms Sales,”; DCSA ReleaseDCSA Major Arms SalesDCSA Press Media TECROSIPRI Arms Transfers Database, Stockholm International Peace Research Institute; US Congressional Record; “Major Arms Sales,” Defense Security Cooperation Agency; “Defense News,” Ministry of National Defense, Republic of China; “Letter from the Ministry of National Defense, Submitting a Written Report on the ‘Implementation Status of US Arms Sales to Taiwan’ for the 2024 Budget Resolution,” Ministry of National Defense, June 12, 2024; and “Excerpt from ‘Ministry of National Defense 2024 Annual Budget Assessment Report’,” Ministry of National Defense, October 2023; and “Information on US Arms Sales to Taiwan,” Ministry of National Defense, October 30, 2024.

Table 1 is an itemized list of FMS cases that are still included in the US arms sale backlog to Taiwan, with the 30mm ammunition sale marked in red to indicate its removal from the backlog.

Sources: Defense Security Cooperation Agency: Press ReleaseUS Congressional Record; “Major Arms Sales,”; DCSA ReleaseDCSA Major Arms SalesDCSA Press Media TECROSIPRI Arms Transfers Database, Stockholm International Peace Research Institute; US Congressional Record; “Major Arms Sales,” Defense Security Cooperation Agency; “Defense News,” Ministry of National Defense, Republic of China; “Letter from the Ministry of National Defense, Submitting a Written Report on the ‘Implementation Status of US Arms Sales to Taiwan’ for the 2024 Budget Resolution,” Ministry of National Defense, June 12, 2024; and “Excerpt from ‘Ministry of National Defense 2024 Annual Budget Assessment Report’,” Ministry of National Defense, October 2023; and “Information on US Arms Sales to Taiwan,” Ministry of National Defense, October 30, 2024.

30mm Ammunition FMS Case Removed from Backlog

In June 2023, Congress received notification of an FMS case for various types of 30mm ammunition valued at $332 million. Taiwan is currently developing an indigenous infantry fighting vehicle called the CM-34 Clouded Leopard that has a 30mm autocannon as its main armament. Increased production of the CM-34 will significantly drive up Taiwan’s demand for this type of munition.

After its initial notification to Congress, information about the 30mm FMS case has been scant. SIPRI’s Arms Transfer Database, our dataset’s primary source of information for weapons deliveries to Taiwan, does not include any information about the 30mm case. Out of an abundance of caution, previous editions of the arms backlog dataset included the 30mm sale. However, based on research conducted by Taiwan Security Monitor’s Joseph O’Connor, we are confident that this sale can be removed from the backlog.

Press reports from Taiwan indicate that in early 2024 Northrop Grumman was working with Taiwan’s Factory 205 to establish a production line for 30mm ammunition in Taiwan. It is not clear when the production run will be fully stood up, or how long it will run. Some components for the shells will be imported from the United States, so the coproduction agreement does not completely insulate Taiwan from US defense industry supply chains. However, moving production of 30mm ammunition to Taiwan will provide some insulation from delays and improve its long-term ability to provide for its own defense. For these reasons we have removed the 30mm FMS case from the backlog.

New Information on F-16 Delays

Delays of Taiwan’s 66 F-16 Block 70/72s, notified to Congress in August 2019 and valued at $8 billion, have increased yet again. Taiwan was originally supposed to receive two of the new aircraft sometime in 2023 with batches of the remaining aircraft arriving in 2024, 2025, and 2026 when delivery would be complete. In October 2024, Taiwan’s defense minister Wellington Koo acknowledged delays in the F-16 case but said that the first aircraft were expected to arrive before the end of 2024.

In January 2025, defense minister Koo provided another update on the F-16 delays, saying that the first aircraft will be delivered in March 2025, over a year behind schedule. Taiwanese press reports mentioned that 19 aircraft were currently on the production line, but it is not clear when these additional aircraft will arrive in Taiwan. The Ministry of National Defense has not revised the final delivery timeline of 2026, but sticking to that timeline will be difficult given the longer than expected wait for the first aircraft.

Contracts Announced for Air Defense Systems

The most significant asymmetric military capabilities that the Biden administration sold to Taiwan were three National Advanced Surface-to-Air Missile System (NASAMS) batteries and mobile L-band radar systems. Taiwan needs a densely layered air defense network that can deny China from achieving air superiority in a war. The NASAMS and radars are a valuable addition to Taiwan’s indigenous air defense capabilities. Congress received notification of both sales in October 2024.  

According to a report by Taiwan’s Central News Agency, Taipei approved contracts for NASAMS and L-band radar systems with effective periods until the end of 2034 and 2030, respectively. It is possible that both arms sales will be delivered before the end of the contract’s effective period, so these dates are not an accurate estimate of the delivery timeline. However, the relatively short gap between congressional notification and contract posting suggests that both arms sales are moving relatively quickly through their program milestones. There is still plenty of time for things to go wrong, but the NASAMS and L-band radar sales are starting on the right foot.  

Conclusion

The Taiwan arms sales backlog is off to a mixed start in 2025. A coproduction agreement for 30mm ammunition is a welcome development, and more such agreements would strengthen Taiwan’s ability to provide for its own defense needs. Contract announcements for NASAMS and mobile L-band radars soon after the announcement of these sales bodes well for on-time delivery of two important asymmetric capabilities.

However, growing delays in the F-16 program are a cause for concern and a reminder that traditional weapons systems like manned fighter aircraft are prone to production delays. We will continue to monitor the F-16 case and post timely updates on its progress.


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