US has burned through ‘years’ of munitions since start of Iran war
Rapid depletion of stockpile including Tomahawk missiles raises pressure on Trump over cost of conflict
The Trump administration has burned through “years” of critical munitions since the start of the war with Iran, said three people familiar with the matter, fuelling concerns about the rising cost of the conflict and the US’s ability to replenish its stockpiles.
The rapid depletion of weaponry included advanced long-range Tomahawk missiles, the people said.
It is a “massive expenditure of Tomahawks”, said one person familiar with the US military’s use of munitions. “The navy will be feeling this expenditure for several years.”
The rising costs will pile pressure on Donald Trump as the war has brought a critical maritime trade corridor to a halt and sent oil prices above $100 a barrel. In a midterm election year, the war is also increasingly unpopular with American voters who face soaring petrol prices and are questioning whether the president has signed the country up for another prolonged conflict in the Middle East.
The Pentagon is expected to submit a formal request to the White House and Congress in the coming days for as much as $50bn in additional spending for the military. The supplemental funding request will set the stage for what is likely to be a fierce funding battle on Capitol Hill that could lay bare growing unease among lawmakers about the administration’s actions.
Lisa Murkowski, a Republican on the Senate appropriations committee charged with approving the federal budget, has warned lawmakers will chafe at any expectation from the White House of a blank cheque.
The Pentagon must “engage” Congress, she said on Thursday.
“You’ve got to be able to provide us with information, as requested, justification,” she said. “Don’t just take for granted that the Congress’s role is basically just to write the cheque.”
Any supplemental bill to fund the war in Iran could face a battle in the House of Representatives and the Senate.
Republicans control the House by a razor-thin margin and fiscal conservatives are likely to recoil at any big outlay of taxpayer money, especially if the White House tries to attach additional public spending such as tariff relief for farmers to a military funding package.
Democratic lawmakers, who have criticised the Iran war as illegal because Trump did not seek congressional approval, are also likely to balk at allocating more money for the Pentagon.
Former Republican Senate majority leader Mitch McConnell on Thursday urged his colleagues “who oppose the president’s use of force against Iran” to approve the military’s supplemental budget request all the same, arguing that it presents an “overdue opportunity to invest in urgent and strategic defence priorities”.
“Weakness invites challenge,” McConnell, a frequent critic of Trump in his second term, said on the Senate floor. “But our adversaries have sought to weaken and undermine America regardless of who the commander-in-chief is.”
Pentagon officials earlier this week told senators that the war had cost more than $11bn in the first six days of strikes. The costs were overwhelmingly for munitions.
“The rounds we’re firing — Patriot rounds, Thaad rounds . . . these weapon systems, each round is millions of dollars,” Democratic senator and Air Force veteran Mark Kelly told MS Now. Meanwhile, the Iranians are “firing cheap drones”, he said, referring to the Shaheds that US intelligence officials say Iran is able to produce quickly for $30,000 a piece.
“The math on this doesn’t work,” Kelly added.
The military is expected to brief Congress on munitions expended in the coming days, a person familiar with the matter said.
US officials have expressed growing concerns in recent years that the use of critical munitions could outpace their production, particularly if the US is drawn into conflicts with adversaries such as Russia or China. This could leave US stockpiles dangerously depleted and the US military less ready to confront future wars.
Murkowski recalled US administrations explaining to Ukraine and European partners in recent years that “we would do more” to help supply them, “but we don’t have the stockpiles”.
“With the level of inventory that [US operations in Iran are] going through on a daily basis, I think we all have reason to ask good questions about how we are doing on munitions,” Murkowski added.
US defence secretary Pete Hegseth last week said: “We’ve got no shortage of munitions. Our stockpiles of defensive and offensive weapons allow us to sustain this campaign as long as we need to.”
White House press secretary Karoline Leavitt on Thursday said: “The US military has more than enough munitions, ammo and weapons stockpiles to achieve the goals of Operation Epic Fury laid out by President Trump and beyond.”
“Nevertheless, President Trump has always been intensely focused on strengthening our armed forces and he will continue to call on defence contractors to more speedily build American-made weapons, which are the best in the world.”
Tomahawks, subsonic cruise missiles with a 1,000lb warhead, are manufactured by US weapons maker RTX at a cost of $3.6mn each.
The US military has bought only 322 of the missiles in the past five years, including the 57 the navy has earmarked for fiscal year 2026 at a cost of $206.6mn. It stands to replenish just a fraction of what it has probably used in recent days.
The US also used at least 124 of the missiles to target Houthi militants in Yemen and Iran’s nuclear facilities in 2024 and 2025. Washington used more than two dozen of the missiles in its attack on the regime’s facility at Isfahan, General Dan Caine, chairman of the joint chiefs of staff, said last June.
The Center for International and Strategic Studies estimated the US used 168 Tomahawks in the first 100 hours of the war that started on February 28.
“It’s a lot. And it will take years to replace,” said one US lawmaker of the Tomahawks, as well as US reserves of Thaad interceptors and Patriot missiles, critical air defences against the barrage of missiles and drones that Iran has unleashed on US and allied assets in the Middle East since the start of the war.
The US is spending “many billions” on a war that is proving deeply unpopular with Americans, Ron Wyden, the top Democrat on the Senate financial services committee, said on Thursday.
The cost of it “goes up practically as we talk”, he said. “It’s an astronomical sum.”