Excuse my ignorance...however, all the calls of Putin being a War Criminal and this would need to be judged by Criminal International Criminal Court.
Is this anything other then just words and condemnation, obviously with the nature of the invasion and civilian strikes there is little argument against it. What is the process if bringing him before the court? Presumably there would need to be some sort of defeat of Russia/capture of Putin to be able to go anywhere? Who is enacting the "arrest"?
The ICC doesn't have any real powers, and in any case Russia withdraw from it, so it's opinion - even if rendered - doesn't necessarily mean anything. When Biden describes Putin as a war criminal it is more rhetoric than statement of anything legal.