Neon is not a product of the Ukraine as a commodity they only have. It is obtained from the air as a trace noble gas. Apparently they have much production facilities for this. We can do the same. I do not know how long it would take to do this. It is simply a hyper cold distillation process.
While it would be possible for any other nation to produce it, it will take a while to redevelop industrial apparatus to do it. Ukraine had made it available in such quantity and at such a low price for the past two decades that all the companies in the US that used to make the gear have either discontinued it long ago or the companies themselves are gone as there was simply no market in the US to sell to.
Well, that IS the question. Even the Chinese apparently don't make much. Russia and Ukraine make the lion's share.