U.S. troops prepare to fire Stinger missiles from their Stryker armored fighting vehicle during Saber Strike military drill in Rutja, Estonia March 10, 2022.
U.S. troops prepare to fire Stinger missiles from their Stryker armored fighting vehicle during Saber Strike military drill in Rutja, Estonia March 10, 2022. Reuters / INTS KALNINS

The U.S. Army has signed a deal to buy $687 million worth of anti-aircraft Stinger missiles to replenish stocks sent to Ukraine, sources said on Friday.

The shoulder-fired anti-aircraft Stinger missiles made by Raytheon Technologies were in hot demand in Ukraine, where they have successfully stopped Russian assaults from the air, and in neighboring European countries who fear they may also need to beat back Russian forces.

The contract for a total of 1,468 Stingers was awarded Wednesday according to a document reviewed by Reuters. There was no timeline for the completion of the work, but it was estimated delivery could take as many as 30 months.

The Pentagon did not immediately respond to requests for comment

U.S. troops have limited use for the current supply of Stingers -- a lightweight, self-contained weapon that can be deployed quickly to defend against helicopters, airplanes, drones and even cruise missiles -- but the United States needs to maintain its supply on hand while it develops the next generation of a "man-portable air defense system."

On May 6 the Pentagon's chief weapons buyer, Bill LaPlante, said that he had aimed to sign a contract by the end of May and that the intent is to replace the Stinger missiles sent to Ukraine one-for-one.

Since February, the U.S. has shipped about 1,400 Stingers to Ukraine. U.S. allies also want to restock the weapons they shipped to Ukraine in recent months.

The Stinger production line was closed in December 2020, the Pentagon has said. Since then, Raytheon won a contract in July 2021 to manufacture more Stingers, but mainly for international governments, according to the U.S. Army.

The sole Stinger facility, in Arizona, only produces at a low rate.