Russian President Vladimir Putin on Tuesday vowed to continue with the year-long war in Ukraine and accused the US-led Nato alliance of fanning the flames of the conflict in the mistaken belief that it could defeat Moscow in a global confrontation.

Speaking nearly a year to the day since the start of the military operation that has triggered the biggest confrontation with the West since the depths of the Cold War, Putin said Russia would "consistently resolve the tasks facing" it in Ukraine.

Flanked by four Russian tricolour flags either side, Putin told the country's political and military elite that Russia was tilting towards Asia after the West slapped on the most severe sanctions in modern history.

Besides the promise to continue the war and warnings to the West of a global confrontation, Putin also sought to justify the war, saying it had been forced on Russia and that he understood the pain of the families of those who had fallen in battle.

The West and would-be Nato member Ukraine reject that narrative, and say Nato expansion eastwards, with Finland and Sweden also applying to join, is no justification for what they say is an imperial-style land grab doomed to failure.

"The people of Ukraine have become the hostage of the Kyiv regime and its Western overlords, who have effectively occupied this country in the political, military and economic sense," Putin said.

"They intend to transform a local conflict into a phase of global confrontation. This is exactly how we understand it all and we will react accordingly, because in this case we are talking about the existence of our country."

Defeating Russia, he said, was impossible.

The 70-year-old Kremlin chief said Russia would never yield to Western attempts to divide its society, adding that a majority of Russians supported the war.

Russian forces have suffered three major battlefield reversals since the war began but still control around one-fifth of Ukraine.

Yevgeny Prigozhin, founder of the Wagner group of Russian fighters, said on Tuesday his fighters had been deprived of munitions.

Tens of thousands of men have been killed, and Putin now says Russia is locked in an existential battle with an arrogant West which he says wants to carve up Russia and steal its vast natural resources. (Reuters)