The US Army has awarded Raytheon a contract worth up to $687 million for Stinger anti-aircraft missiles to replenish stockpiles that have been sent to Ukraine, Reuters reported on Friday.

Since Russia invaded Ukraine on February 24, the US has shipped 1,400 Stinger missiles to Ukraine. The US Army hasn’t purchased Stingers since 2005 as it has been planning to upgrade to the next generation of shoulder-fired anti-aircraft missiles.

But the US policy of sending thousands of Stingers to Ukraine has put the aging weapon in high demand, and Raytheon, the former employer of Secretary of Defense Lloyd Austin, stands to make long-term profits on the war.

Producing the Stingers could take time as Raytheon CEO Greg Hayes has said the company may not be able to manufacture more until 2023. According to Military Times, because some components are no longer commercially available, Raytheon may need to redesign the Stingers’ seeker head.

The US has also shipped over 5,000 Javelin anti-tank missiles to Ukraine since Russia invaded. Javelins are a joint project between Raytheon and Lockheed Martin. President Biden recently visited a Lockheed plant producing the anti-tank missiles in Alabama in a show of support for the arms maker.

As part of the massive new $40 billion aid package President Biden signed for Ukraine, the Pentagon will receive $8.7 billion to replenish its stockpiles of Stingers, Javelins, and other weapons being sent to Ukraine. The package also provides about $11 billion in presidential drawdown authority, which allows Biden to ship weapons to Ukraine from the US military’s stockpiles.