"The Kiev regime supplies the media with lies about crimes against humanity allegedly committed by Russian troops in Izyum," Stepanov told Sputnik on Friday.
"We are talking about another monstrous provocation, about an attempt to stage 'Bucha' in a new way. All this is being done on the eve of the opening of the High-Level Week of the UN General Assembly to try to manipulate a certain part of the western public on the subject of Ukraine."
That western media and officials immediately pick up "fabrications of Kiev" about the alleged crimes against humanity in Izyum without double-checking is simply an indicator of how aggressive the information war against Russia is, Stepanov added.
He also said that he is optimistic that the truth about Izyum will come out, just as it did with the alleged use of chemical weapons in Syria.
On Friday, Ukrainian authorities alleged that mass burial sites were found in Izyum after Russian troops withdrew from the Kharkov region in early September, and that more than 400 bodies had been found so far.
Russia's Defense Ministry has warned several times that the Kiev regime supported by the collective West has been preparing Bucha-style provocations to accuse Russia of war crimes.
On 24 February, Russia began a military operation in Ukraine, responding to calls for help from the breakaway republics of Donetsk and Lugansk. Moscow has said that the aim of its operation is the "demilitarization and de-Nazification" of Ukraine.
Western countries have responded by imposing comprehensive sanctions against Russia, while accusing Moscow of crimes against humanity, including alleged atrocities in the city of Bucha. The Kremlin has denied the allegations, and has accused Kiev of employing typical terrorist methods, such as hiding behind civilians and deploying weapons in civilian areas.