The United States has spent an estimated US$37.5 billion on its war with Iran, according to Defense Secretary Pete Hegseth, as the Trump administration pressures Congress to approve tens of billions of dollars in additional military funding.
Hegseth disclosed the updated figure while appearing before the Senate Appropriations Committee on July 21, 2026. The estimate represents an increase of nearly US$8 billion from the Pentagon’s previous publicly disclosed figure of approximately US$29 billion in May.
The new total includes anticipated military costs through September 30, the end of the current US financial year. That means it is not simply a calculation of money already spent, but a Pentagon estimate of what ongoing operations are expected to cost over the coming months.
The administration is seeking a broader US$87.6 billion supplemental funding package from Congress. Of that amount, approximately US$67.15 billion would be directed to the Department of Defense, with much of the money connected to the continuing conflict with Iran.
Where the additional money would go
The Pentagon says the funding is required to maintain current military operations, replenish weapons and ammunition, repair equipment, increase production capacity and prevent budget shortfalls across the armed forces.
Modern warfare can consume expensive missiles, interceptor systems and precision-guided weapons at an extraordinary rate. The Pentagon reportedly wants billions of dollars to accelerate the production and replacement of advanced missiles and other munitions that have been used extensively throughout the conflict.
US military officials have argued that the additional funding is not only about replacing weapons already fired. They say it is also necessary to ensure that American forces remain prepared for other potential conflicts and emergencies around the world.
Hegseth described the requested funding as urgent, warning that military branches could face serious financial pressure without additional congressional support. The Pentagon has reportedly begun shifting billions of dollars from other areas to sustain its current operations.
However, critics argue that emergency funding should not become a way of avoiding normal budget scrutiny or disguising the full long-term cost of the war.
The cost has continued to rise
The Pentagon’s estimates have increased rapidly since the conflict began.
During the opening six days of the war, the Trump administration estimated that military operations had cost more than US$11 billion. By late April, officials placed the figure at approximately US$25 billion. In May, the estimated total increased again to around US$29 billion.
Hegseth’s latest figure of US$37.5 billion shows that the projected cost has risen by nearly US$8 billion since that May estimate.
These numbers cover direct military spending, but they may not represent the complete economic cost of the conflict. Future medical treatment for injured service members, veterans’ support, replacement of military equipment, interest on borrowed money and broader economic disruption could increase the eventual total.
Wars frequently cost considerably more than their initial public estimates, especially when there is no clear timetable for ending combat operations.
Congress questions the administration
The funding request has faced scrutiny from lawmakers who want clearer information about the administration’s military objectives, spending plans and exit strategy.
During the Senate hearing, Hegseth faced questions about how the Pentagon calculated the US$37.5 billion estimate and why such a large supplemental request was needed after Congress had already approved enormous levels of defence spending.
Democratic lawmakers have accused the administration of escalating American involvement without presenting a convincing strategy for ending the conflict. Some have warned that the United States risks becoming trapped in another expensive and prolonged Middle Eastern war.
Republicans have generally been more supportive of the administration’s military campaign, although concerns have also been raised about the size of the request and whether every item contained in the package is directly connected to the Iran conflict.
The overall proposal contains funding for military and non-military priorities. Critics have argued that grouping unrelated spending into an emergency war package could make it more difficult for the public to understand exactly where the money is going.
A much larger defence budget
The supplemental request comes as the Trump administration pursues a proposed US$1.5 trillion defence budget for the following financial year.
Supporters say the higher spending is necessary to strengthen the US military, rebuild weapons stockpiles and prepare for growing competition with countries including China, Russia and Iran.
Opponents argue that the Pentagon is already receiving historically high levels of funding while essential domestic services face pressure. They question why additional war spending should be approved without equivalent scrutiny of its effect on public debt, healthcare, education, housing and the cost of living.
Because much of the proposed funding is not matched by spending reductions or new revenue, it would likely be financed through additional government borrowing.
That means the cost would not disappear after Congress approved it. Interest payments could continue for years, placing an additional burden on future taxpayers.
No clearly defined endpoint
The most important question may not be how much the war has cost so far, but how much it could eventually cost.
The administration has defended the campaign as necessary to weaken Iran’s military capabilities and prevent Tehran from obtaining a nuclear weapon. Hegseth and other officials have argued that failing to confront Iran could create even greater security and economic costs in the future.
However, the administration has not provided a clear public timetable for ending military operations.
Without a defined endpoint, Congress could face repeated requests for additional funding. The US$67.15 billion currently being sought for the Pentagon may therefore not represent the final request connected to the conflict.
The earlier estimates demonstrate how quickly the financial demands of war can grow. A conflict initially measured in days has already generated tens of billions of dollars in projected spending.
The human cost remains central
Financial figures can dominate political debate, but the consequences of war cannot be measured only in dollars.
American service members have been killed and injured, while people across Iran and the wider region have faced deaths, displacement, damaged infrastructure and continuing insecurity.
Military spending also reflects weapons being deployed, bases being operated, aircraft being flown and personnel being placed in dangerous environments.
As the conflict continues, lawmakers must consider both the financial cost to taxpayers and the human consequences for everyone affected.
What happens next
Congress must decide whether to approve the administration’s supplemental request, reduce it, alter its conditions or demand greater oversight.
Supporters of the package will argue that withholding funds during active military operations could place American personnel at risk and weaken the country’s ability to defend itself.
Critics will argue that approving another massive funding package without a clear strategy could deepen US involvement and make an already costly war even harder to end.
The Pentagon now estimates that the conflict will have cost US$37.5 billion by the end of September. The administration is requesting another US$67.15 billion for the military as part of a wider US$87.6 billion package.
The numbers are already enormous, but without a clear endpoint to the war, they may only be the beginning.