The US military has exhausted nearly 80% of its interceptors for a key missile defense system as senior US military commanders are warning that the Pentagon’s munitions stockpile is “dangerously low,” according to multiple sources familiar with the matter.

Stockpiles of key air defense systems have been particularly depleted during the war with Iran. The US military has burned through nearly four-fifths of its THAAD missile inventory compared to pre-war numbers and roughly half of its Patriot interceptors since the start of the war, according to two sources familiar with the latest inventory report. The disclosure of the low THAAD inventory has not been previously reported.

The Center for Strategic and International Studies estimates the United States had around 2,200 Patriots (of the platform’s two most-modernized variants) and 452 THAAD missiles in its stockpile before the Iran war started.

Gulf countries have also raised fresh concerns about how a shortage of air defense systems could impact their ability to ward off potential Iranian retaliation if President Donald Trump decides to escalate the ongoing conflict.

Several of those countries rely on US air defense systems and have acknowledged the stockpile shortage could hinder their own ability to intercept incoming Iranian missile and drone attacks – particularly if they are targeted in response to any American escalation, multiple officials said.