Speaking at a meeting with veterans, Putin said Moscow had long sought to negotiate a settlement to the conflict in Ukraine's Donbas, an eastern industrial region where Russia-backed separatists have battled Ukrainian forces since 2014.

``Large-scale combat operations involving heavy weapons, artillery, tanks, and aircraft haven't stopped in Donbas since 2014,'' Putin said. ``All that we are doing today as part of the special military operation is an attempt to stop this war. This is the meaning of our operation - protecting people who live on those territories.''

Putin insisted again that Russia tried to negotiate a peaceful settlement to the separatist conflict before sending in troops, and said ``we were just duped and cheated.''

He described Ukraine's east as Russia's "historic territories,'' adding that Moscow conceded their loss after the 1991 collapse of the Soviet Union but had to act to protect Russian speakers there.

Putin has explained his decision to send troops into Ukraine on Feb. 24 by citing a need to protect Russian speakers, as well as to pursue the ``demilitarization'' and ``denazification'' of Ukraine to prevent the neighboring country from posing a threat to Russia.

Ukraine and its Western allies have rejected the rationale as a cover for an unprovoked act of aggression.

Meanwhile, Russian President Vladimir Putin said Wednesday he had "no doubt" Moscow would emerge victorious in Ukraine, despite military setbacks in the nearly year-long offensive.

Despite a number of military defeats, victory was "guaranteed, I have no doubt about it," Putin told workers at a factory in Russia's second city Saint Petersburg.

"The unity and solidarity of the Russian people, the courage and heroism of our fighters, and of course, the work of the military-industrial sector" will secure victory, he added.

Putin also praised the Russian defense industry "We have something to rely upon and this cannot but inspire that victory will be ours," he said.

Putin attended the meeting with veterans during a visit to St. Petersburg for the 80th anniversary of the Red Army breaking the Nazi siege there on Jan. 18, 1943.

The blockade of the city, which was then called Leningrad, lasted nearly 900 days and only fully lifted in January 1944, marking one of the bloodiest pages of World War II. About 1 million people died in Leningrad during the siege, most of them from starvation.

Putin on Wednesday laid a wreath at the city's Piskaryov memorial cemetery, where 420,000 civilian victims of the siege and 70,000 Soviet soldiers were buried. He also put flowers in a section where his brother, who died as a child during the siege, was buried in a mass grave.

Putin also visited a defense factory in St. Petersburg, where he promised workers more social benefits and draft deferments. He said the ``courage and heroism of our soldiers`` and defense industry efforts would secure Russia's victory.

Speaking energetically but frequently clearing his throat, Putin said Russia produces three times as many air defense missiles as the United States.