US missile defences may take years to rebuild after Iran war, says Pentagon

The United States will need years to replenish its missile defences following the war against Iran, a top US military official said on Wednesday.

General Heath Collins, director of the Pentagon's Missile Defence Agency, told a congressional hearing that it will take a "number of years" to fully recover its stockpile of interceptors.

The US and its regional allies used thousands of interceptors to defend against Iranian missile and drone attacks during the six-week conflict.

Analysis by British defence think tank RUSI found that almost 4,200 defensive munitions were expended by the US, Israel and the Gulf states in the first 16 days of the war.

Stockpiles for the US's THAAD system, Israel's Arrow and David's Sling, and Patriot batteries in the Gulf were close to being fully depleted by the final week of March, it said.

American-made interceptors are expensive and slow to produce. THAAD manufacturer Lockheed Martin makes fewer than 100 interceptors each year, with a single unit costing as much as $15 million.

The US and its allies also deployed thousands of offensive munitions during the conflict. The US and Israeli air forces used more than 7,110 bombs and missiles during the first 16 days, according to RUSI.

US news media have reported that the US Navy fired more than 850 Tomahawk missiles during the first four weeks of the war. More than 2,000 missiles were fired in the opening weeks of the conflict.

The six-week war is believed to have cost the US tens of billions of dollars. The White House has until now declined to provide an exact figure for the conflict, though the Pentagon has said it cost more than $11 billion in the first week alone.

Defence Secretary Pete Hegseth requested an additional $200 billion in emergency funding to replenish munitions and cover other costs of the war, equivalent to a fifth of the Pentagon's 2026 budget.