Russian President Vladimir Putin has justified his invasion of Ukraine and criticized the Western nations that support Kyiv in his Victory Day speech.

Russia on Tuesday marked the 78th anniversary of the victory over Nazi Germany in World War Two with a ceremony in Moscow's Red Square.

Putin told Russian soldiers and veterans gathered at the square that a "real war" has once again been unleashed against their homeland.

He vowed to repel what he calls "international terrorism," protect the people of Donbas and ensure Russia's security. Moscow unlawfully annexed Donbas and other Ukrainian regions last year.

He urged the Russian people to unite further and stressed that his special military operation in Ukraine will continue.

Putin made no reference to Wednesday's drone attacks on the Kremlin. His officials called the incident a Ukrainian assassination attempt on the leader.

After the speech, Russian weaponry such as the short-range ballistic missile Iskander and the nuclear-capable ICBM Yars were on display.

The celebration in the capital seemed much scaled down from last year as a flyover of warplanes was canceled.

In more than 20 cities across the country, military parades were canceled for security reasons.

Meanwhile, the Russian presidential office announced that the leaders of seven former Soviet republics attended the ceremony in Moscow, apparently to demonstrate unity as tensions mount between Russia and the West.

US think-tank the Institute for the Study of War said earlier that in 2022 no foreign leaders attended the Moscow Victory Day celebration, and Kazakhstan, Kyrgyzstan and Uzbekistan cancelled their parades, citing health risks from the COVID pandemic.