The U.S. Army has used up much of its 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 U.S. 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 are an important part the military's arsenal, allowing accurate strikes from a safe distance. U.S.-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.