The Ukraine War, is beyond the kinetics, a war of propaganda and misinformation. Thus, we need to take what either side says, not with just a grain of salt, but a salt mine. However, al viewpoints of the major players need to be considered. Thus, the head of Russia’s mercenary group, Wagner, Yevgeny Prigozhin, said that he thought that Putin could deploy nuclear weapons on the Belgorod region on the border with Ukraine, which is Russian territory. This would be a kind of “mad dog” strategy to show that Russia is not messing around, bombing itself, and Ukrainians to boot. However, Prigozhin also said that the tactical nuke may not work, given how the Russians neglect their equipment. But, I would not be too sure of that, and would not bet the sheep farm on it.
https://nypost.com/2023/06/06/wagner-boss-afraid-putin-may-use-nuclear-weapons-in-russia/