The US Army has used up much of its global stockpile of highly accurate long-range missiles during its five-month war with Iran, according to three people familiar with the data, raising concerns about the military’s readiness for future conflicts.

The missiles are principally the Army’s surface-to-surface weapons, known as Army Tactical Missile Systems (ATACMS) and Precision Strike Missiles (PrSM). The US has used “virtually all” of these weapons, according to two of the sources.

The degree to which the military is running out of ATACMS and Precision Strike Missiles has not been previously reported.

The long-range munitions – which cost more than $1 million each – are an important part of the military’s arsenal, allowing accurate strikes from a safe distance. US-supplied ATACMS have played a key role in the war in Ukraine, allowing Ukrainian forces to attack targets inside Russia. The PrSM is a newer, more advanced generation that will replace the ATACMS, which have a shorter range.

The dramatic rundown in precision, long-range missiles means US President Donald Trump may have to rely more on riskier, piloted bombing missions if he relaunches large-scale attacks on Iran.

The sources declined to say how many of each munition the US had left.

Trump launched the Iran war jointly with Israel in February, predicting that the conflict would last a short time.

But as the war drags on, the three people familiar with the matter expressed worry that the falling missile supplies could limit the US ability to deter adversaries, including Russia and China.

A fourth person familiar with the matter said that despite the high usage of precision weapons, the US can resupply. Central Command — which oversees US forces in the Middle East — has been able to reload from US military supplies around the world, the person said.

The sources interviewed for this story spoke on the condition of anonymity.

Asked for comment on the stockpile data, the White House issued a statement from Trump, saying the US had “far more munitions than anyone in the world” and “far more than we need.”

“Our defense companies are, at this moment, making more munitions than they have ever made before, in addition to expanding their plants and equipment at record levels,” Trump said.

Analysts agree that certain munitions, including artillery shells and several types of missiles, are being produced at record levels but caution that supplies might fall short of what is needed for a prolonged war.

Lockheed Martin, which makes the ATACMS and PrSMs, along with the anti-ballistic missile THAAD system, did not immediately respond to questions about Trump’s statements or about supply levels. Raytheon, which makes Tomahawk missiles and Patriot interceptors, two important US weapons, also did not immediately respond.

Responding to a request for comment, chief Pentagon spokesperson Sean Parnell said: “America’s military is the most powerful in the world and has everything it needs to execute at the time and place of the President’s choosing. We have executed multiple successful operations across combatant commands while ensuring the US military possesses a deep arsenal of capabilities to protect our people and our interests.”

The supply figures have circulated inside the federal government over the last week during tense conversations inside the Trump administration about how much longer the US can continue striking Iran without drawing down the stockpile to levels that would limit the military’s ability to respond to crises elsewhere.

WARNINGS OVER WEAPONS SUPPLIES

One of the sources said the drawdown of the ATACMS and PrSM stockpiles reflected a decision by the Trump administration to avoid riskier ways of attacking Iranian targets, such as by using piloted aircraft to drop bombs.

Because these weapons allow the military to attack targets from a distance, analysts say they would be valuable in a war against an adversary with strong air defenses, such as China. They have been used to strike targets inside Iran, according to a March report by the Center for Strategic and International Studies (CSIS).

According to the report, PrSM stockpiles were low to start with, since it is a relatively new munition, but the US military has ordered a large number of them for 2027. The Army has said that ATACMS are being phased out and that production is shifting to the newer PrSM missiles.

Military leaders have for weeks warned the president that stockpiles of defensive weapons — including Patriot interceptors, which are effective against ballistic missiles — were dwindling, said two of the sources. Last week, several media outlets reported Trump had decided not to launch another massive offensive inside Iran in part because his military advisers had warned about the US stockpile.

A US official disputed those accounts, saying Trump chose not to move forward with another attack because of pressure from Gulf states.

The Middle East conflict has sparked intense debate about Trump’s authority to prosecute hostilities against Iran without congressional authorization. No request for a declaration of war or an authorization to use military force has been submitted to Congress.

DEFENSIVE WEAPON STOCKS ARE ALSO DIMINISHED

Last week, CSIS published a report estimating that between February and July about 65% of Patriot interceptors had been expended and that the number of THAAD ballistic missile interceptors in US stockpiles was at least 38% lower than at the start of the war. Patriots and THAADs are systems that detect and destroy incoming missiles and are among the most effective in the country’s arsenal.

While Reuters has not seen the supply figures, those numbers match internal US data, two of the sources said.

The US also burned through a little less than half of its global supply of Tomahawk cruise missiles, which are generally launched from ships, since the start of the war, one of the sources said.

Reuters could not independently verify that number.

The Tomahawk is a Navy weapon, launched from destroyers, cruisers and submarines, and has long served as the sea service’s principal means of striking heavily defended targets without risking pilots.

Raytheon, a unit of RTX RTX.N, has reached a tentative multi-year agreement with the Pentagon aimed at boosting Tomahawk production, alongside increases in other munitions, as Washington races to rebuild stockpiles.