The 71-year-old Putin has ruled Russia since the turn of the century.
Moscow: President Vladimir Putin on Thursday warned his nuclear forces were "always" on alert and added that Moscow would not tolerate any Western threats, during an address on the annual Victory Day parade.
In a defiant speech on Red Square before thousands of soldiers dressed in ceremonial attire, Putin heaped praise on his army fighting in Ukraine and accused "Western elites" of fomenting conflicts around the world.
"Russia will do everything to prevent a global clash, but at the same time we will not allow anyone to threaten us. Our strategic forces are always on alert," Putin told the crowd.
"Dear friends, Russia is now going through a difficult, crucial period. The fate of the Motherland, its future depends on each of us," he said.
The May 9 parade marks the Soviet Union's defeat of Nazi Germany in World War II and has become Russia's most important public holiday as Putin puts the country firmly on a combat footing.
Putin has used nuclear rhetoric throughout the conflict but has grown increasingly belligerent since last year, pulling out of a nuclear test ban treaty and a key arms reduction agreement with the United States.
Earlier this week, he ordered the Russian military to hold nuclear drills involving the navy and troops based near Ukraine, raising fears he could use the powerful weapons on the battlefield.
In comments recorded on Tuesday but released by the Kremlin after the parade, Putin vowed to modernise his army's weaponry and said Russia would use whatever foreign parts it could get to make them.
"Modern military technology is changing very fast. If we want to be successful, we always have to be one step ahead," he said in a meeting with army commanders.
'Russia is with you'
Putin has repeatedly framed the current fight against Ukraine as an existential battle against "Nazism", a message he reiterated in his address Thursday.
"We bow our heads before the memory of civilians killed by barbaric shelling and terrorist attacks by neo-Nazis," he said.
"Those on the front line, on the line of contact -- are our heroes. We bow before your steadfastness and self-sacrifice, selflessness. All Russia is with you," he continued.
Russia's border regions including Belgorod have been hit by repeated deadly Ukrainian attacks since the conflict began, including on Thursday when overnight aerial bombardment injured eight people.
Security in the capital was tight ahead of this year's parade, amid repeated Ukrainian strikes on Russian territory and after an Islamic State attack on a concert hall near the capital in March killed dozens.
Other parts of Russia including the western Kursk and Pskov regions cancelled their parades due to security concerns.
The parade featured columns of Russian military equipment, although was notably scaled back compared to past years as Moscow mobilises its resources for the Ukraine front.
"We come to see it every year," said 44-year-old Yelena Melikhova, who watched the procession of military equipment heading to Red Square.
"It's very touching, very exciting."
Svetlana Sycheva, 48, who watched the parade said she was filled with "pride".
"Even in such difficult times we have the opportunity to rejoice, and to feel the emotions that we have just experienced," she told AFP.
'We will win'
Russia often invites representatives from countries it deems "friendly" to the event, though attendance had dwindled even before it sent troops into Ukraine in early 2022 amid a stand-off with the West.
Nine world leaders attended Thursday's parade -- the heads of ex-Soviet republics Belarus, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan -- as well as the leaders of Cuba, Laos and Guinea-Bissau.
The 71-year-old Putin has ruled Russia since the turn of the century, securing a fresh six-year mandate in March after winning presidential elections devoid of all opposition.
Russia's army held off a much-hyped Ukrainian counter-offensive last year, and it has since made gains on the front lines as Kyiv struggles with ammunition and manpower shortages.
Thursday's festivities come two days after Putin vowed at a lavish inauguration to deliver "victory" to Russians.
"We are a united and great nation, and together we will overcome all obstacles, realise everything we have planned, and together, we will win," he said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)