A US senator said it is “shocking” how much of America’s crucial weapon stockpiles have been used in its war against Iran.

After hearing the Pentagon’s classified briefing on the figures, Mark Kelly warned it would “take years” to replenish its arsenal of advanced missiles that were originally built for a potential war with China.

The senior Democratic senator from Arizona told CBS News in an interview on Sunday, “It is shocking how deep we have gone into these magazines.” He listed how the Pentagon had exhausted its numbers of Tomahawk and Atacms precision missiles, as well as Thaad and Patriot interceptor rounds.

“We have been expending a lot of munitions, and that means the American people are less safe, whether it’s a conflict in the western Pacific with China or somewhere else in the world, the munitions are depleted,” the retired astronaut and naval officer added.

At the end of April, the Pentagon estimated that its war with Iran, codenamed Operation Epic Fury, had so far cost approximately $25 billion.

Analysts have warned that the conflict has also highlighted the US military’s overreliance on exceedingly expensive missiles and munitions and raised concerns over whether the defence industry can adapt to producing lower cost arms, particualrly attack drones, quickly enough.