President Vladimir Putin on Tuesday slammed what he called attempts to rewrite history at a Moscow ceremony marking the 70th anniversary of the liberation of Auschwitz.
Speaking at a Jewish museum in Moscow, he said Nazi Germany's crimes including the Holocaust could be neither forgiven nor forgotten.
"Any attempts to hush up these events, distort, re-write history are unacceptable and immoral," said Putin, who is conspicuously staying away from the main events in Poland in a gesture laying bare divisions with the West over the war in Ukraine.
In the run-up to the ceremony Poland angered Moscow when its foreign minister, Grzegorz Schetyna, said it was Ukrainian soldiers – rather than the Soviet army – who liberated the camp.
Moscow blasted Warsaw for twisting history for political ends.
Putin has repeatedly condemned the West for what he calls attempts to belittle the Soviet army's role in the victory over Nazi Germany in 1945 and to glorify Nazi collaborators in eastern Europe and ex-Soviet republics such as Ukraine.
At the ceremony, Putin also drew parallels with the current Ukraine crisis which has sent Moscow's ties with the West to post-Cold War lows and seen imposition of punishing Western sanctions against Russia.
"We all know how dangerous and destructive are double standards, indifference to and disregard for another man's fate as is the case with the current tragedy in eastern Ukraine," the Kremlin strongman said at the Jewish Museum and Tolerance Center.
Putin's absence at the main ceremony at Auschwitz-Birkenau, which is now a museum, raised eyebrows at home since the camp was liberated by the Soviet Red Army on January 27, 1945.
In 2005, Putin traveled to Poland to participate in a ceremony marking the 60th anniversary of the liberation of Auschwitz.
Russian officials said earlier that Putin had received no formal invitation to fly to Poland.
AFP contributed to this report.