The body of Bolshevik leader Vladimir Lenin should stay in its mausoleum on Red Square in Moscow, so long as Russians retain personal memories of the Soviet period, President Vladimir Putin said Thursday.

Asked at his annual press conference whether the embalmed body of the first Soviet leader, who died in 1924, should be removed, Putin said his position had not changed but also criticised the way Lenin set up the USSR.

"In my view we should not touch this, at least while we have very many people who connect their own lives with this... connect this with achievements of the past, of the Soviet years," said Putin.

Liberals regularly raise the question of removing Lenin's body for burial and more than 60% of Russians support this according to a 2017 survey by VTsIOM state pollster.

However, the topic remains highly controversial in a country where the Communist Party is still the largest opposition faction in parliament.

Communist Party leader Gennady Zyuganov in 2017 said Putin had promised him that Lenin's body would not be moved on his watch.

But former KGB agent Putin also admitted his own view of Lenin had changed over time, saying the USSR's first leader had made mistakes and "was less a statesman and more a revolutionary".

"As you know for a long time I worked in espionage, which was the main activity of a very politicised organisation, the KGB of the USSR, and I had my ideas about our leaders," said the 67-year-old.

But he added that "from the position of my experience today, I understand that as well as the ideological aspect there is also the geopolitical."

Lenin, by creating a confederation of ethnic-based republics that did not quite match geographic locations of communities, created thousands of "pressure points," where conflict could break out, Putin said.

The Soviet state was also too closely entwined with the Communist Party, and could not survive once the authoritarian party leadership lost its grip, he added.

"As soon as the party started cracking, started crumbling, the country followed by starting to crumble," said Putin, who has called the 1991 breakup of the USSR the biggest geopolitical tragedy of the 20th century.

"That was a mistake, a fundamental mistake in state building," he said.