Putin lays flowers at Eternal Flame near Kremlin wall on WWII Victory Day. Photo tass.com

MOSCOW - President Vladimir Putin told Russians they are "invincible" when they stand together as the country on Saturday marked the 75th anniversary of the end of World War II in lockdown from the coronavirus.

With cases surging and authorities urging Russians to stay in their homes, celebrations of this year's Victory Day were muted after the Kremlin postponed plans for a grand parade with world leaders.

Instead of columns of military hardware and thousands of troops marching through Red Square as planned, Putin walked alone to lay flowers at the Eternal Flame outside the red brick walls of the Kremlin.

In a solemn televised speech, he made no mention of the virus, despite Russia having the fifth-highest number of confirmed infections in the world.

Putin instead highlighted the sacrifices made by the Soviet Union in what Russians call the Great Patriotic War and hinted at the threat now facing the country.

"Our veterans fought for life, against death. And we will always be equal to their unity and endurance," Putin said.

"We know and firmly believe that we are invincible when we stand together."

An honour guard marched past Putin after his speech, as Russian television showed images of Red Square empty under cloudy skies.

Military helicopters, bombers and fighter jets flew over the city, releasing smoke in the red, white and blue of the Russian flag.

Putin then oversaw a modest procession of soldiers in dress uniform inside the Kremlin walls, promising them in a brief speech that "all plans for development of the army and navy will be realised". AFP