President Vladimir Putin said on Tuesday that what was at stake in Ukraine was Russia's very existence as a state.

Speaking at length to workers at an aviation factory in Buryatia, some 4,400 km (2,750 miles) east of Moscow, Vladimir Putin expanded on his familiar argument that the West was bent on pulling Russia apart.

"So for us this is not a geopolitical task, but a task of the survival of Russian statehood, creating conditions for the future development of the country and our children," he said.

Vladimir Putin has accused the West of using Ukraine as an tool to wage war against Russia and inflict on it a "strategic defeat". The United States and its allies say they are helping Ukraine to defend itself from an imperial-style invasion that has destroyed Ukrainian cities, killed thousands of civilians and forced millions to flee their homes.

Vladimir Putin said in a response to a question that he had been worried about the economy when the West imposed unprecedented waves of sanctions last year but it had proved stronger than expected.

"We have increased our economic sovereignty many times over. After all, what did our enemy count on? That we would collapse in 2-3 weeks or in a month," he said.

He said the enemy had been expecting that factories would grind to a halt, the financial system would collapse, unemployment would rise, protesters would take to the streets, and Russia would "sway from within and collapse".

"This did not happen," Vladimir Putin said. "It turned out, for many of us, and even more so for Western countries, that the fundamental foundations of Russia's stability are much stronger than anyone thought."