President Vladimir Putin on Friday charged NATO member Poland with having territorial ambitions in the former Soviet Union and warned any aggression against Russia's close ally Belarus would be considered an attack on Russia.

Moscow would react to any aggression against Belarus, which forms a loose "Union State" with Russia, "with all the means at our disposal," Putin told a meeting of his Security Council in televised remarks.

"Belarus is part of the Union State (of Russia and Belarus). And unleashing aggression against Belarus would mean aggression against the Russian Federation. We will respond to this with all means at our disposal," Putin told a meeting of the National Security Council on Friday.

Poland said earlier on Friday that it intended to move an as-of-yet-unknown number of its own soldiers further east because of the presence of Russian Wagner mercenaries in neighboring Belarus.

On Wednesday, Wagner chief Yevgeny Prigozhin was shown in a video welcoming his fighters to Belarus, telling them they would take no further part for now in the war in Ukraine but ordering them to gather strength for Wagner's operations in Africa while they trained the Belarusian army.

Prigozhin says Wagner, which led the conquest of the Ukrainian city of Bakhmut, is Russia's most effective fighting force. But his frequent clashes with the Moscow defense establishment led him to stage an armed mutiny four weeks ago.

The insurrection ended with an agreement that Wagner fighters – many recruited from prison – could move to Belarus if they wished.

On Thursday, Minsk said Wagner mercenaries had started to train Belarusian special forces at a military range just a few miles from the Polish border.

In the midst of the war he launched against Ukraine, Putin also accused Poland of intending to occupy western Ukraine.

There were reports about the allegedly planned creation of a Polish-Lithuanian-Ukrainian military unit, he said. The unit would be deployed in Ukraine "allegedly to ensure the security of what is now western Ukraine," Putin asserted. "But basically, if you call a spade a spade, it is about the subsequent occupation of these territories."

"It is well known that they also dream of the Belarusian lands," he said.

"But as far as Belarus is concerned, it is part of the Union State; unleashing aggression against Belarus will mean aggression against the Russian Federation," Putin said. "We will respond to this with all the means at our disposal."

Poland denies any territorial ambitions in Belarus.

Russia has in recent weeks begun stationing tactical nuclear weapons in Belarus for the first time. The Kremlin said Putin would meet Belarusian President Alexander Lukashenko, with whom he speaks regularly, in Russia on Sunday.

German Defense Minister Boris Pistorius said on Friday that Germany and NATO were prepared to support Poland in defending the alliance's eastern flank.

"The pathetic bore from the Kremlin is once again repeating lies about Poland and also trying to falsify the truth about the war against Ukraine," Poland's deputy minister coordinator of intelligence services Stanislaw Zaryn told state-owned PAP news agency.

"Vladimir Putin is also using historical revisionism again to spread false accusations against Poland."

Putin also stated that Poland should not forget that the gain of former German territories in the west after World War II was a "gift from Stalin."

After World War II the Allied powers and the Soviet Union met at key conferences and decided on the postwar map of Europe. Poland was awarded some land in its west that had been German for hundreds of years, but the Soviet Union took over areas in Poland's east that had been Polish for a long time.

"Vladimir Putin is once again using historical revisionism to spread false accusations against the Republic of Poland," said Zaryn, on Twitter.

Higher-ranking Polish officials have so far not responded to Putin's comments.