Russian President Vladimir Putin on Monday stressed the "special military operation" in Ukraine was the "only right decision" for his country during a speech at an annual event to mark the 77th anniversary of the Soviet Union's victory over Nazi Germany in World War II.

In a public address during Victory Day celebrations at Red Square in central Moscow, Putin justified sending troops into Ukraine as a "pre-emptive rebuff to aggression" from member countries of the North Atlantic Treaty Organization, saying the security bloc had created an "absolutely unacceptable threat."

Russian President Vladimir Putin attends a military parade during the 77th anniversary of the Victory Day in Red Square in Moscow on May 9, 2022. (Anadolu Agency/Getty/Kyodo)

Again labeling the Russian invasion a "special military operation," he did not use the highly symbolic anniversary to formally declare war on Ukraine as some had expected.

More than two months after invading Ukraine, Putin instead blamed the West for not responding to Russia's calls for "honest dialogue," and criticized the provision of weaponry and other military equipment to Ukraine.

His speech was followed by a military parade featuring around 11,000 troops and around 130 military vehicles, including new tanks and intercontinental ballistic missile launchers.

Russia canceled the air portion of the parade, citing unfavorable weather. The flyover was set to feature 77 aircraft, including the Ilyushin Il-80, a so-called "doomsday" plane from which the president would issue commands in the event of a nuclear war.

Victory Day is considered the most patriotic date on the Russian calendar, with celebrations taking place across the country. It has been celebrated with increasing fanfare under the Putin administration, which turned to nationalism to foster unity.