The United STATES never did any such thing.
2/3 of the representatives of those States united must, sitting in the Senate, ratify ANY such "guarantee" to make it binding, and that never happened.
The voice of sanity finally.
I agree the Senate never signed anything.
However see
Budapest Memorandum on Security Assurances
https://en.wikipedia.org/wiki/Budapest_Memorandum_on_Security_Assurances
If I was Ukraine I would think we had been “guaranteed”!