The US has used up years' worth of ammunition stocks since the start of the war with Iran

The administration of US President Donald Trump has depleted stocks of key munitions intended to last for years following the outbreak of war with Iran. This has been reported by three sources familiar with the situation.

In particular, this refers to the rapid deployment of high-precision, long-range Tomahawk cruise missiles. This was reported by The Public, citing the FT.

“This is a massive expenditure on Tomahawk missiles,” said one of the sources familiar with the US military’s use of munitions. According to him, the navy will feel the effects of such expenditure for several years.

The rising costs are intensifying political pressure on Donald Trump. The conflict has led to the closure of a vital maritime trade route and pushed oil prices above $100 a barrel.

In a mid-term election year, the war is becoming increasingly unpopular among American voters, who are facing rising fuel prices and questioning the need for a new protracted conflict in the Middle East.

The Pentagon is expected to approach the White House and Congress in the coming days with a request for up to $50 billion in additional defence funding.

This request could spark a fierce political battle in Congress, where some lawmakers have expressed concerns about the administration’s actions.

Republican Senator Lisa Murkowski, a member of the Senate Budget Committee, stated that lawmakers would not support unconditional funding.

“You must provide us with the information and justification we have requested,” she said. “It should not be taken for granted that Congress’s role is merely to write a cheque.”

Any bill on additional war funding could face resistance in both the House of Representatives and the Senate.

Republicans hold a slim majority in the House of Representatives, and some conservative lawmakers oppose significant budgetary expenditure. Additional tension could arise from the possible inclusion of other expenditure in the defence package, notably support for farmers.

Democrats may also oppose additional funding for the Pentagon. They have previously stated that a war with Iran would be illegal, as President Trump has not secured congressional approval.

Former Senate Majority Leader Mitch McConnell urged lawmakers to support additional military funding.

“Weakness invites challenges,” he said in the Senate. “But our adversaries seek to weaken and undermine America regardless of who is commander-in-chief.”

Earlier this week, Pentagon officials told senators that the war had cost over $11 billion in the first six days of strikes alone. The bulk of these costs were for ammunition.

Democratic Senator Mark Kelly, a former Navy fighter pilot, stated that a single shot from a Patriot or THAAD system costs millions of dollars.

Meanwhile, Iran is using significantly cheaper Shahed drones, which, according to US intelligence, may cost around $30,000 per unit to produce.

“The numbers don’t add up,” Kelly said.

The military is expected to hold a further briefing for Congress on the use of ammunition in the near future.

In recent years, US officials have increasingly expressed concern that ammunition consumption could outpace production rates. This is particularly relevant in the context of potential conflicts with adversaries such as Russia or China.

Lisa Murkowski recalled that in previous years, US administrations had explained to Ukraine and European partners that the scope for assistance was limited due to insufficient weapons stocks.

“Given how US forces’ stocks in Iran are dwindling daily, I believe we all have reason to ask legitimate questions about the state of our ammunition stocks,” she said.

US Defence Secretary Pete Hagseth stated last week that the US has no ammunition shortage.

“We have no shortage of ammunition. Our stocks of defensive and offensive weapons allow us to continue this campaign for as long as necessary.”

White House Press Secretary Caroline Levitt also stated that the US military has sufficient stocks of weapons to carry out the tasks of Operation Epic Fury.

“The US armed forces have more than enough stocks of ammunition, supplies and weapons to achieve the objectives of Operation Epic Fury, as set out by President Trump, and even more.”

She added that Donald Trump would continue to urge defence companies to speed up the production of American weapons.

The Tomahawk cruise missiles, with a 1,000-pound warhead, are manufactured by RTX. The cost of a single missile is approximately $3.6 million.

Over the past five years, the US military has purchased only 322 such missiles, including 57 planned for the Navy in the 2026 financial year.

Previously, the US used at least 124 Tomahawk missiles during strikes against the Houthis in Yemen and against Iranian nuclear facilities in 2024 and 2025.

General Dan Kane, Chairman of the Joint Chiefs of Staff, reported that more than two dozen missiles were used during the attack on a regime facility in Isfahan.

According to estimates by the Center for International and Strategic Studies, in the first 100 hours of the war, which began on 28 February, the US used 168 Tomahawk missiles.

One US lawmaker stated that it could take years to replenish stocks of Tomahawks, as well as THAAD interceptors and Patriot missiles.

Senator Ron Wyden, the leading Democrat on the Senate Finance Committee, said the US was spending “many billions” on a war that was becoming increasingly unpopular among Americans.

“The cost of this is rising practically before our very eyes,” he said. “It is an astronomical sum.”