Russia's lower house of parliament, the State Duma, has passed a statement saying the World War II Katyn massacres were committed on the direct order of Soviet dictator Josef Stalin.
Konstantin Kosachyov, chairman of the Duma's Foreign Affairs Committee, called the document "historic."
"We do not want to raise the Katyn issue to a new level of internal or international discussions," he added. "We want to close this issue."
The 1940 massacre of some 20,000 Polish officers and other prominent citizens in western Russia by Soviet secret police has long soured relations between the two countries.
The Soviet Union initially blamed the massacre on the Nazis.
The resolution, opposed by the Communist Party, said it was time to lay waste to the myths spread by "official Soviet propaganda." It also stressed that Soviet citizens were also victimized by Stalin's repressions.
"I am troubled that over the past few decades the Russians have been put on their knees and forced to apologize for everything, including things they have never done," said Viktor Ilyukhin, a Communist deputy.
The head of the Polish parliament's Foreign Affairs Committee, Andrzej Halicki, said he considered the Duma's statement to be a breakthrough. "I am happy that such a process of reconciliation and truth is taking place," he said.
President Dmitry Medvedev is scheduled to visit Poland in early December.
compiled from agency reports