MOSCOW, RUSSIA -- Columns of tanks and troops paraded through Moscow on Wednesday as President Vladimir Putin presided over grand Second World War commemorations to stir up patriotic fervour ahead of a vote on extending his rule.

Putin was flanked on Red Square by elderly war veterans in uniforms laden with medals as thousands of troops carrying bright banners and Kalashnikov rifles marched in the blazing sun to mark the Soviet Union's defeat of Nazi Germany.

Forced to postpone the traditional May 9 Victory Day celebrations by the coronavirus pandemic, Putin rescheduled the parade for just a week ahead of a July 1 public vote on controversial constitutional reforms.

Among other changes, the reforms Putin proposed earlier this year would reset his presidential term-limit clock to zero, allowing him to run two more times and potentially stay in the Kremlin until 2036.

"It is impossible even to imagine what the world would be if the Red Army hadn't come to defend it," the Russian president said in an address to troops following a minute of silence to remember soldiers who died in the fighting.

Putin hailed the Soviet Union's role in World War II praising the Red army for liberating Europe, ending the Holocaust and saving Germany from Nazism, adding it was "our duty to keep this in mind".

He announced the new dates last month for both parade and vote -- initially planned for April -- despite Russia still recording thousands of new coronavirus cases every day.

The rate of new infections has fallen in recent weeks and cities including Moscow have lifted anti-virus lockdowns, but critics accuse Putin of rushing ahead with public events to pursue his own political ends.

This year's parade, marking 75 years since the Nazi defeat showcased some 14,000 troops from 13 countries, as well as vintage equipment and the latest military hardware showing off Russia's fighting capabilities.

Officials say the date was chosen to coincide with the anniversary of the first post-war parade on Red Square, which saw Soviet troops throw down Nazi standards in front of the Lenin mausoleum on June 24, 1945.

CONTAGION FEARS

In his two decades in office, Putin has harnessed the legacy of the Soviet victory to boost patriotic sentiment and support for his government.

Ahead of the parade, he slammed the West for "insulting Russia" by playing down the USSR's role in winning the war.

Chinese leader Xi Jinping and French President Emmanuel Macron had been scheduled, before the pandemic, to stand shoulder-to-shoulder with the Kremlin chief at the parade, in a testament to Russia's growing international influence under Putin.

Instead he was flanked by the heads of former Soviet Union countries such as Belarus president Alexander Lukashenko.

With more than 8,000 recorded fatalities and over 600,000 confirmed infections, Russia has the third-largest coronavirus caseload in the world after the United States and Brazil.

The Kremlin said safety precautions were being taken in the lead-up to the parade -- but participants were not wearing masks and there is still a ban on mass gatherings in Moscow.

Dozens of regions decided to drop their own commemorative parades, citing concerns that a spike in cases could overwhelm under-funded and poorly equipped hospitals throughout the country.

Yet events marking the Soviet victory were scheduled to go ahead in Saint Petersburg, Volgograd and Simferopol in Russia-annexed Crimea.

Reflecting virus concerns, both Moscow Mayor Sergei Sobyanin and Kremlin spokesman Dmitry Peskov advised people to watch the procession on television rather than attend in person. The veterans were quarantined ahead of the event in sanatoriums.

Precautions are also being taken for the constitutional vote, with early balloting starting on Thursday and continuing through to the official vote day on July 1.

Chief opposition figure and former presidential hopeful Alexei Navalny has criticised authorities for spending vast sums on the parade and urged his supporters to boycott the ballot.

"One crazy, greedy man who has gone mad with power is making the whole country engage in delirium," he said.