So... are we going to honor our agreement from 1993 now that we’ve admired the fact that Russia is invading?
The USA has no such agreement with the Ukraine.The memorandum (if that is what you are in reference to) signed when the Ukraine gave up its nukes is just that, a memorandum and is not a treaty or akin to a treaty in any way.
Was this "agreement" submitted to the Senate for ratification?
No? Didn't think so.
The President cannot involve the united States in international disputes and conflicts without the binding authority conferred by the representatives of the several states.