Is there a legitimate reason not inviting Ukraine to the upcoming negotiation with Russia?

I despise Putin and his minions as much as any sane persons out there. That said, I’m not entirely sure if there are any potentially legitimate reasons to exclude Ukraine from the first round of negotiations. Surely there must be at least some arguments that could potentially justify such a seemingly unfair arrangement? (otherwise such arrangement is just too ridiculous and immoral to me)

If I were to play devil’s advocate, I might argue that Russia is extremely reluctant to participate in any negotiations as long as Ukraine is present. Therefore the negotiation delegation could be trying to maximize the chances of Russia’s attendance, at least in the early stages, by excluding Ukraine from the first round of discussions.

To be honest, the argument above is far from persuasive or reasonable to me. But maybe there are perspectives I’m failing to see. Also I’m too afraid to ask this question in any other subs because people really, really hate Putin and Russia right now (and for good fucking reason).