Well, yes, it is an invitation. But NATO didn't let the Ukraine join, that was blocked by at least Germany. And on during his visit in Moscow, Chanceller Scholz

Well, yes, it is an invitation. But NATO didn't let the Ukraine join, that was blocked by at least Germany. And on during his visit in Moscow, Chanceller Scholz basically offered Putin that Ukraine joining into NATO could be very far in an undetermined future.