What territories does Russia claim Ukraine has irrevocably lost, and what is Russia's position on territorial concessions?

According to Russia's UN Ambassador, Ukraine has irrevocably lost several territories including Crimea, Donetsk, Luhansk, Kherson, and Zaporizhzhia - all regions that Russia has annexed. This stance represents Russia's firm position on the territorial aspect of the ongoing conflict. Reinforcing this position, Russian Foreign Minister Sergei Lavrov has explicitly dismissed any possibility of making territorial concessions to Ukraine. These statements collectively indicate Russia's unwavering stance that these annexed territories are now permanently part of Russia, establishing a clear precondition for any potential peace negotiations with Ukraine.