Russian leader Vladimir Putin lamented during his annual end-of-year press conference Thursday that communist mass murderer Vladimir Lenin had made the “strange” decision in the establishment of the Soviet Union to place “Russian” territories within the Ukrainian socialist republic.

Putin lamented that, thanks to Soviet planners failing to follow divide the Union by where ethnic groups actually lived, Russia now contends with thousands of “sort points” of ethnic tension that require a delicate hand to diffuse.

Ukrainian officials objected to Putin’s comments, particularly in the context of Putin illegally annexing part of Ukraine in 2014 and currently engaging in an ongoing invasion of Ukraine’s eastern Donbas region. Russia claims those attempting to carve an ethnic Russian state out of Donbas are independent “rebels,” not Russians, and any Russia participating in the civil war is a “volunteer” with no ties to the Russian government.

Putin has traditionally held a multi-hour press conference in anticipation of the Christmas holiday where he answers questions on a variety of domestic and international affairs.

The Russian news agency TASS did not specify why Putin was discussing 20th-century Soviet history. The longtime head of government reportedly lamented the inefficiency of Soviet planning and ethnic tensions he blamed on poor choices made by Lenin himself

“By his [Lenin’s] decisions, ethnic groups were tied to concrete territories, and then they got the right to secede from the Soviet Union. But even the territories had been carved up in such a way that they did not always correspond and still don’t coincide now with the traditional places of domicile of any given ethnicity,” Putin said. “Sore points sprung up right away, and they are still in place in relations between the former Soviet republics. Moreover, there are 2,000 such points inside the Russian Federation.”

Putin then turned to Ukraine, which he said benefitted territorially by inheriting “Russian” territory.

“We have just discussed with my Ukrainian colleague our relations, but when the Soviet Union was being set up, the original, ancestral Russian territories, which had never had anything to do with Ukraine — the entire Black Sea region, Russia’s western lands — went to Ukraine with a strange wording ‘to increase the percentage ratio of the proletariat in Ukraine’,” Putin alleged. “This was a somewhat bizarre decision, but this did happen. All this is the legacy of Vladimir Ilyich Lenin’s state building and we have to grapple with this now.”

Of the territories that Putin already controls, he warned, “if you let things go for even a second, there will be hell to pay.”

Putin’s criticism of Lenin did not go as far as to support efforts to exhume him, which apparently also came up at the press conference.

“As for [Lenin’s] body, I believe it should be left as it is, at least as long as there are those, and there are quite a few people here who link their lives, their fates as well as certain achievements of the past, the achievements of the Soviet era with that,” TASS quoted Putin as saying. The news agency did not offer any context as to what the comment was a response to.

Ukraine’s Foreign Affairs Ministry rapidly dismissed Putin’s claims that much of Ukraine is originally Russian.

“We condemn any attempts by the Russian Federation to encroach on the territorial integrity of Ukraine,” Deputy Foreign Minister Vasyl Bodnarhe said on Friday, making the reverse claim that much of what exists currently in Russian borders should belong to Ukraine. “Let’s turn to history: who belonged to whom? Once upon a time, Moscow was subordinated to Kyiv, so let’s talk about the roots, not what grew after.”

Former Ukrainian Secretary of the National Security and Defense Council (NSDC) Oleksandr Turchynov went further, contending that most of modern Russia should not be governed out of Moscow.

“If we separate from Russia those territories that were annexed by blood, violence, betrayal and lies, the ‘originally Russian’ swamps remaining after that could easily fit within one Moscow region,” he said.

Russia is currently embroiled in a civil war to strip Kyiv of control of Donetsk and Luhansk, the two provinces of the Donbas region, both of whom contain violent insurrections declaring each a sovereign Russian republic. Putin has claimed not to have a direct hand in the violent pro-Russian gangs of the Donbas but has regularly equipped them with supplies, sending a 96th Russian “humanitarian aid” convoy into the Donbas on Friday, over loud Ukrainian objections. Russia claims the convoy contains “Christmas gifts,” which Ukrainian officials have expressed doubt about.

The Ukrainian government argues that Putin is attempting to annex Donbas the same way he did the Crimean Peninsula, which belonged to Ukraine until Russia invaded it in 2014. To ease tensions in Donbas, Ukrainian President Volodymyr Zelensky met with Putin in Paris last month, with German Chancellor Angela Merkel and French President Emmanuel Macron as intermediaries. Putin claimed he was “happy” with the results of the talks, while Zelensky lamented the affair as frustrating and useless, calling Putin a “difficult” person to negotiate with.

Follow Frances Martel on Facebook and Twitter.