Moscow and Warsaw feud over who was to blame for WWII

Poland and Russia have again clashed over who was to blame for unleashing World War II, each accusing the other of distorting history and trying to undermine already strained relations.

Tensions are running high between Warsaw and its Soviet-era master, with NATO and EU member Poland fearing what it has described as Russian military adventurism and imperialist tendencies.

"We have greeted with concern and disbelief the statements by representatives of the Russian Federation, including President Vladimir Putin, on the genesis and the course of World War II, which misrepresent the events," the Polish foreign ministry said in statement Saturday.

Warsaw criticised Moscow for "renewing Stalinist propaganda" and "wasting" reconciliation efforts and what it said were the achievements of former leaders Mikhail Gorbachev and Boris Yeltsin in trying to improve ties.

The ministry also spoke of the suffering of Poles and Poland and "hostile" Soviet actions both before and during the war, estimating the number of Polish victims of Soviet repression at 566,000.

In Moscow, a foreign ministry spokeswoman retorted that it was Poland that had "undermined" relations with its "aggressive rhetoric and demolishing of monuments to fighters of fascism".

It also accused Poland of being the leading mover in the EU sanctions slapped on Russia over the Ukraine conflict, which were this month extended by Brussels for another six months.

Last week, Russian President Vladimir Putin blamed the Western powers and Poland for World War II, pointing to various treaties signed with Nazi Germany before the conflict began in 1939.

He also lashed out at the European Parliament over a September resolution on "Europe's historical memory" which he said virtually accused the Soviet Union of starting World War II and put it on a par with the Nazis.

"But to equate the Soviet Union (with) Nazi Germany... is incredible cynicism," he said. "This means that people do not know history, they cannot read or write!" Poland has often appealed to its EU and NATO partners to guard against "appeasing" Moscow.

It has cultivated close ties with the United States, which it regards as the primary guarantor of its security within NATO and a bulwark against Russia's military might.

Most recently, Poland has, along with its Baltic neighbours and Ukraine and the United States, voiced strong opposition to the Nord Stream 2 project to supply Russian gas to Europe.

US President Donald Trump last week signed off on sanctions on companies working on the pipeline project, which some say will increase Europe's dependence on Russia for its energy supplies.