Poland summoned the Russian ambassador to protest recent claims made by Russian President Vladimir Putin about the causes of World War II, according to the Polish deputy foreign minister.

"We are ready to explain to Russian diplomats historical facts [or] as long as it will take [in order] for them to understand that the world will never forget the true meaning of the Ribbentrop-Molotov Pact," Marcin Przydacz wrote on Twitter on Saturday.

Earlier this month, Putin criticized a European Parliament resolution which stated that the 1939 non-aggression pact between Nazi Germany and the Soviet Union, named after the diplomats who signed it in Moscow, "paved the way for the outbreak of World War II."

During the meeting with Ambassador Sergey Andreev, Poland's Foreign Ministry voiced strong protest against "historical insinuations" made by Putin and the head of the Russian parliament, Vyacheslav Volodin, Przydacz told Poland's PAP news agency.

Andreev, who was summoned to Poland's Foreign Ministry on Friday, called the talks "tough but civil."

It is only the latest dispute between the two Slavic nations over how to remember the war.

Poles remember being invaded by both Nazi Germany and the Soviet Union at the start of a conflict that left 6 million of its people dead. Warsaw considers both powers to have been aggressors who unleashed mass suffering and death.

Russia focuses on the Soviet sacrifices that came after Germany invaded the Soviet Union in 1941, which brought the Soviets into the war on the side of the Allies. Some 27 million Soviet citizens died in the fight to free Europe from Nazi terror.

Putin has called the EP resolution "sheer nonsense."

The war began days after Adolf Hitler and Soviet dictator Josef Stalin agreed to carve up Poland and the Baltic states based on a secret protocol in the Molotov-Ribbentrop pact they signed on Aug, 23, 1939.

Putin has been casting the Molotov-Ribbentrop treaty as a move the Soviet Union was forced into following nonaggression agreements some other European nations had signed with Hitler.

He cited a 1938 agreement reached by Germany, Britain, France and Italy that allowed Hitler to annex Czechoslovakia as an example of Western leaders' alleged "collusion" with Hitler.

Putin cited archive documents that he claimed showed the Polish ambassador to Berlin praising Hitler's plans to rid Europe of Jews.

In an angry outburst, Putin denounced the ambassador as a "scum" and "anti-Semitic swine."