Israel lambasted Russian Foreign Minister Sergei Lavrov on Monday for claiming Adolf Hitler had Jewish origins, saying it was an "unforgivable" falsehood that debased the horrors of the Nazi Holocaust.
Leaders from several Western nations denounced the foreign minister's comments and Ukrainian President Volodymyr Zelenskiy accused Russia of having forgotten the lessons of World War Two.
In a sign of sharply deteriorating relations with Moscow, the Israeli foreign ministry summoned the Russian ambassador and demanded an apology.
"Such lies are intended to accuse the Jews themselves of the most horrific crimes in history that were committed against them," Israeli Prime Minister Naftali Bennett said in a statement.
"The use of the Holocaust of the Jewish people for political purposes must stop immediately," he added.
Lavrov made the assertion on Italian television on Sunday when he was asked why Russia said it needed to "denazify" Ukraine if the country's own president, Volodymyr Zelenskiy, was himself Jewish.
"When they say 'What sort of nazification is this if we are Jews', well I think that Hitler also had Jewish origins, so it means nothing," Lavrov told Rete 4 channel, speaking through an Italian interpreter.
"For a long time now we've been hearing the wise Jewish people say that the biggest anti-Semites are the Jews themselves," he added.
Zelenskiy, in his nightly video message, noted Moscow has been silent since Lavrov's comments. "This means that the Russian leadership has forgotten all the lessons of World War Two," he said. "Or perhaps they have never learned those lessons."
US Secretary of State Anthony Blinken weighed in later on the comments by his Russian counterpart saying it was "incumbent on the world to speak out against such vile, dangerous rhetoric."
The German government's anti-Semitism commissioner, Felix Klein, said Lavrov's remarks mocked the victims of Nazism and "shamelessly confront not only Jews but the entire international public with open anti-Semitism."
Italian Prime Minister Mario Draghi called the top Russian diplomat's comments obscene, while Canada's Justin Trudeau expressed disbelief.
Dani Dayan, chairman of Yad Vashem, Israel's memorial to the 6 million Jews killed in the Holocaust, said the Russian minister was spreading "an anti-Semitic conspiracy theory with no basis in fact".
The identity of one of Hitler's grandfathers is not known but there has been some speculation, never backed up by any evidence, that he might have been a Jew.
There was no immediate response to requests for comment from the Russian embassy to Isra el or from Lavrov in Moscow.
Israeli Foreign Ministry Yair Lapid, whose grandfather died in the Holocaust, said accusing Jews of being anti-Semites was "the basest level of racism". He dismissed Lavrov's assertion that pro-Nazi elements held sway over the Ukrainian government and military.
"The Ukrainians aren't Nazis. Only the Nazis were Nazis and only they dealt with the systematic destruction of the Jewish people," Lapid told the YNet news website.
Israel has expressed support for Ukraine following the Russian invasion in February. But wary of straining relations with Russia, a powerbroker in neighbouring Syria, it initially avoided direct criticism of Moscow and has not enforced formal sanctions on Russian oligarchs.
However, relations have grown more strained, with Lapid last month accusing Russia of committing war crimes in Ukraine.
The Ukrainian president has also run into flak in Israel by looking to draw analogies between the conflict in his country and World War Two. In an address to the Israeli parliament in March, Zelenskiy compared the Russian offensive in Ukraine to Nazi Germany's plan to murder all Jews within its reach during World War Two.