Zelensky, in shifting the burden of responsibility for providing guarantees, is constantly requesting security guarantees from the West and Russia, without his government providing any security guarantee that NATO will not expand eastward.
On the contrary, he himself fervently desires ΝΑΤΟ to expand to the East by annexing Ukraine.
Instead of apologizing for NATO expansion and giving security guarantees that NATO will shrink or dissolve, he demands security guarantees from the Russians on behalf of NATO. In other words, all Zelensky guarantees, is that it will remain alive, and that it will continue to expand.