Russian President Vladimir Putin has memorialized victims of World War Two on a visit to St. Petersburg. The city was the scene of a fierce battle against Nazi Germany.

Putin laid flowers at a monument to the several hundred thousand people who died in a siege during the war.

He compared that conflict to Russia's action in Ukraine, saying the recent action was aimed at stopping a "war" that had been raging in the eastern Ukraine region of Donbas since 2014.

Putin said it is important to be able to respond to new threats to his country.

He said, "We have to remember what happened during the war so that such a tragedy will never happen again."

In August, Putin decided to increase the total number of Russian troops to about 1.15 million.

Defense Minister Sergei Shoigu on Tuesday disclosed that Putin decided to further expand that number to 1.5 million.

A Russian presidential office spokesperson called the decision a response to a proxy war waged by the United States and its Western allies.