Speaking today at the opening of a memorial to the victims of purges, Putin said "political repressions have become a tragedy for our people" and dealt a blow to the nation, the consequences of which are still felt today.
Putin said "millions of people were declared enemies of the people on absurd charges, executed, mutilated and went through the suffering in prisons and labor camps."
He emphasised that there could be no justification for the repressions, adding that "our duty is not to allow oblivion."
The statement marks the strongest condemnation yet of Soviet-era repressions from Putin, who has taken a cautious line on the nation's Soviet-era history, trying to focus on its achievements rather than on Communist crimes.