There is a known treaty about full banning nuclear tests, from 1996. Many states have signed it, but not all ratified. I can understand, why, for example, DPRK haven't signed it - it is critical for their national security.
We all know, that US foreign politics is oriented towards peace, and I remember some claims about fully banning nuclear weapons (from Obama times).
But why has the US not ratified it, if so? Were there some public claims about origin of this non-ratification?