US expenditure on the ongoing conflict with Iran has already surpassed $45.1 billion. The Department of Defense formally submitted this figure to the US Congress on Friday (September 18), a fact confirmed to CNN by two sources familiar with the matter.

Sources indicate that direct war costs stood at $43.6 billion as of September 3. An additional $1.5 billion was added for fuel costs. However, this calculation does not include the cost of repairing damaged US bases and facilities; consequently, the actual expenditure could be higher.

Last July, the Pentagon reported that spending had reached $37.5 billion up to that point. The updated figure shows a significant increase. Lawmakers had requested a detailed breakdown of both direct and indirect costs, but one source stated that the Pentagon did not provide such details.

The Pentagon's figure exceeds the estimate provided by the Congressional Budget Office (CBO). The CBO had projected spending of around $38 billion as of August 1—a figure that also excluded repair costs. The agency noted that a large portion of the total expenditure went toward purchasing and utilizing weaponry. The CBO warned that if the war continues, additional monthly costs could range from $2 billion to $3 billion, a figure that could rise further if the conflict intensifies.

The CBO further indicated that a prolonged war could lead to increased inflation in the US during the first quarter (January–March) of 2027. This additional military spending could place further strain on the economy at a time when the general public is already concerned about the financial situation.

The conflict involving the US, Israel, and Iran began on February 28. In the initial day's attacks, several top leaders and senior officials—including Iran's Supreme Leader Ayatollah Ali Khamenei—were killed. In retaliation, Iran launched counter-attacks against the US, Israel, and American installations across the Middle East. The war has effectively spread across the entire Gulf region. Disruptions to shipping in the Strait of Hormuz have raised concerns regarding global fuel supplies and driven up fuel prices.

Several nations, including Oman, Qatar, and Pakistan, have undertaken diplomatic initiatives to halt the conflict. However, the conflict has not yet fully ceased.