The Sejm voted to approve a text that accuses Soviet Red Army troops of war crimes against Poles in 1939 when they entered what are now the western sectors of Ukraine and Belarus, but which at the time were part of Poland, RIA Novosti reported.
"On September 17, 1939, the Soviet forces committed an act of aggression against Poland, violating its sovereignty and trampling on the statutes of international law," the document reads. "The grounds for the Red Army's invasion were given by the Molotov-Ribbentrop Pact, signed on August 23, 1939 in Moscow between the Soviet Union and Hitler's Germany," the document reads.
Warsaw also classified as genocide the execution of thousands of Polish POWs by the Soviets in western Russia's Katyn Forest in 1940.
Russian NATO envoy Dmitry Rogozin last week accused Poland's leaders of "Russophobia" in their views on the Second World War's outbreak, saying, "The Polish version is a lie and the attitude of the Polish leadership is provocative."