Mexico has an embassy in Kyiv.
Mexico might have its people from the Kyiv and Moscow embassies craft a draft agreement that could be made public.
Both the Ukrainian and Russian people want the war to end.
The Swiss also have embassies in both countries.
The American proposal from I suppose the Witkoff talks has already been splashed.
https://freerepublic.com/focus/f-chat/4333177/posts