Polish Prime Minister Mateusz Morawiecki delivers a speech for the 10th anniversary of the Auschwitz Foundation on December 6, 2019 in Oswiecim, Poland | Omar Marques/Getty Images Polish PM accuses Putin of ‘deliberate’ lies in WWII spat Russian president had called Polish ambassador to Nazi Germany ‘scum and an anti-Semite pig.’

Polish Prime Minister Mateusz Morawiecki accused Russia's president on Sunday of "deliberately" lying about Poland "on numerous occasions," in response to Vladimir Putin's recent comments regarding Polish involvement in the outbreak of World War II.

“President Putin has lied about Poland on numerous occasions, and he has always done it deliberately. This usually happens when Russian authorities feel international pressure related to their activities — and the pressure is exerted not on historical but [the] contemporary geopolitical scene,” Morawiecki said in a written statement.

He added that “in recent weeks Russia has suffered several significant defeats,” including the failed attempt to “take complete control over Belarus,” the further extension of EU sanctions, problems with finalizing the Nord Stream II gas pipeline, and a ban on Russian athletes participating in international sports events.

Earlier in December, Putin on several occasions disputed a European Parliament resolution that argued that the 1939 non-aggression deal between Nazi Germany and the Soviet Union helped pave the way for World War II to break out. Putin called it “a sheer nonsense,” and instead pointed to the 1938 Munich Agreement, which allowed Adolf Hitler to annex Czechoslovakia, and the benefits Poland got from the pact, as an international agreement that started the war.

During an annual military meeting, he also described the Polish ambassador to Nazi Germany as "scum and an anti-Semite pig.”

“He expressed full solidarity with Hitler in his anti-Semitic views,” he added.

Russia’s ambassador to Warsaw was summoned to the Polish Ministry of Foreign Affairs on Friday, after Polish officials declared they would "stand up against historical insinuations."

Over the years, the Polish government has objected to any public allegations that the country bears responsibility for helping Germany commit the Holocaust during World War II. In 2018, Morawiecki's government passed a law that made any comments about Polish compliance with Nazi war crimes a civil offense.