Dmitriy Utkin is the founder and leader of PMC Wagner.  Utkin is being designated for being responsible for or complicit in, or having engaged in, directly or indirectly, actions or policies that threaten the peace, stability, sovereignty, or territorial integrity of Ukraine; and for acting or purporting to act for or on behalf of, directly or indirectly, PMC Wagner.

https://home.treasury.gov/news/press-releases/sm0114