Dmitry Medvedev, deputy chairman of Russia's Security Council, said on Saturday that President Donald Trump's assertion that the US had done more than any other country to win World War Two was "pretentious nonsense."
Trump posted on social network Truth Social late on Thursday that "nobody was close to us in terms of strength, bravery, or military brilliance" in both world wars, and that "we did more than any other country, by far, in producing a victorious result in World War II."
Medvedev, a former Russian president who has emerged as one of Moscow's most outspoken anti-Western hawks since the start of Russia's war in Ukraine, made his own statement at a time when Washington and Moscow are trying to reset their troubled ties while discussing a possible way to end the conflict.
"Trump recently announced that the US made the biggest contribution to victory in World War Two and that he will introduce a special holiday on May 8. A holiday is not a bad thing, but his first statement is pretentious nonsense," Medvedev said in a post on the VK social network.
"Our people sacrificed 27 million lives of their sons and daughters in the name of destroying accursed fascism. Therefore, Victory Day is ours and it is May 9! So it was, so it is, so it will always be!" wrote Medvedev.
Russia-Ukraine could see a temporary ceasefire
Medvedev additionally added that nobody could guarantee that the Ukrainian capital of Kyiv would survive to see May 10 if Ukraine attacked Moscow during World War Two victory celebrations on May 9.
Russian President Vladimir Putin on Monday declared a three-day ceasefire in May in the war with Ukraine to mark the 80th anniversary of the victory of the Soviet Union and its allies in World War Two.
The Kremlin said the 72-hour ceasefire would run on May 8, May 9 - when Putin will host international leaders including Chinese President Xi Jinping for celebrations to commemorate victory over Nazi Germany - and May 10.
Responding to Moscow's offer of the three-day ceasefire, Ukrainian President Volodymyr Zelensky said he was ready as long as the ceasefire would be 30 days in length, something Putin had already ruled out in the near term, saying he wants a long-term settlement, not a brief pause.
Zelensky said Ukraine, given the continued war with Russia, could not guarantee the safety of any foreign dignitaries who came to Moscow for the traditional May 9 victory parade.
"We cannot be responsible for what happens on the territory of the Russian Federation. They are responsible for your security, and therefore we will not give you any guarantees," he said.
Medvedev called Zelensky's statement a "verbal provocation" and said nobody had asked for Kyiv's security guarantees for the May 9 events.
"(Zelensky) understands that in the event of a real provocation on Victory Day, nobody will be able to guarantee that Kyiv will live to see May 10," Medvedev said on his official Telegram channel.