The Russian embassy in Germany said on Wednesday that Berlin's decision to approve the delivery of Leopard 2 tanks to Ukraine meant it was abandoning its "historical responsibility to Russia" arising from Nazi crimes in World War Two.
In a scathing statement, the embassy said that the tank deliveries would escalate the conflict to a new level and lead to "permanent escalation".
"This extremely dangerous decision takes the conflict to a new level of confrontation and contradicts the statements of German politicians about the unwillingness of the Federal Republic of Germany to be drawn into it," Ambassador Sergei Nechayev said.
"It destroys the remnants of mutual trust, causes irreparable damage to the already deplorable state of Russian-German relations, and casts doubt on the possibility of their normalization in the foreseeable future," he added.
Kyiv has for months asked for Western tanks that it says it desperately needs to give its forces the firepower and mobility to break through Russian defensive lines and recapture occupied territory in the east and south.
Russia has said such weapons will only prolong the war and prolong Ukrainian suffering, and that the West is "deluded" to think otherwise.
"Berlin's choice means the final refusal of the Federal Republic of Germany to recognize its historical responsibility to our people for the terrible, timeless crimes of Nazism during the Great Patriotic War, and the consigning to oblivion of the difficult path of post-war reconciliation between Russians and Germans," Nechayev said.
"With the approval of the leadership of Germany, battle tanks with German crosses will again be sent to the 'eastern front', which will inevitably lead to the deaths of not only Russian soldiers, but also the civilian population."