They are meant to assist the armed forces restore and preserve US weapons programs: The Pentagon will in future permit protection firms to make use of workers in Ukraine – no less than “far from the front.”
https://www.spiegel.de/ausland/russland-angriffskrieg-us-ruestungsfirmen-duerfen-laut-pentagon-personal-in-der-ukraine-einsetzen-a-92524256-2ae7-46b4-a6e7-0c8cc49712b5#ref=rss