Russia's ambassador to Poland said that Russia bears partial responsibility for the start of the Second World War.
Warsaw is to summon ambassador Sergey Andreyev after he claimed in a TV interview that Poland had blocked the formation of a coalition against Nazi Germany several times before the war broke out, by it being invaded by Hitler's forces.
The comments come as relations between Moscow and its east European neighbour worsen. Last week, the Polish ambassador to Moscow was summoned after the graves of Soviet soldiers in the village of Milejczyce were vandalised. The Polish government condemned the vandalisation.
Poland "bears partial responsibility for the catastrophe that ensued in September 1939", Andreyev argued in an interview with a private Polish TV station. He went to claim that the Soviet invasion of Poland in 1939 was not an act of aggression, but a defensive act to ensure the safety of the USSR. This invasion led to Poland being partitioned between Nazi Germany and Soviet Russia.
In the interview, Andreyev appeared to be referring to Poland's decision disallow Soviet troops to travel through Poland in the build-up to the war was the provocation for Russia's forces moving in.
The Russian ambassador said that relations between Poland and Russia were at their lowest ebb since 1945 and that Poland had frozen political, cultural and humanitarian relations with its neighbour.
The Polish Foreign Ministry said Andreyev had "undermined historical truth". It said: "We take it as a lack of respect for the memory of the victims of the NKVD [Soviet secret police]," referring to those killed during the Soviet occupation.