Russian President Vladimir Putin may officially declare war on Ukraine on May 9, instead of his "special military operation. This would allow the Kremlin leader to mobilize reserve forces as much as possible by throwing in new Ukrainian territories, U.S. and European officials believe, CNN reported.

As noted, Putin is likely to want to announce either some kind of military achievement in Ukraine, or instigate a major escalation of hostilities, or both messages together, for Russia's Victory Day celebrations.

Western officials are now considering a scenario with a declaration of war, given Russia's huge losses in strength and equipment in Ukraine.

"I think he will try to abandon his 'special operation.' He was spinning the information field, preparing the ground to be able to say, 'Look, it's a war against the Nazis now, and I need more men. I need more Russian cannon fodder," British Defense Secretary Ben Wallace recently noted to LBC radio.

He also conceded that a similar statement could have been made on the May 1 holiday.

On Monday, U.S. State Department spokesman Ned Price said there was "good reason to believe that the Russians will do everything they can to use" May 9 for propaganda purposes.

"We've seen the Russians really redouble their propaganda efforts, probably almost certainly to distract from their tactical and strategic failures on the battlefield in Ukraine," he told a briefing at the State Department and added that there are "rumors that Russia may officially declare war" on May 9.

"It would be a great irony if Moscow were to use 'Victory Day' to declare war, which in itself would allow them to increase the number of conscripts in a way they cannot do now. In a way that would be tantamount to revealing to the world that their military efforts are failing, that they are drowning in their military campaign and military objectives," the State Department spokesman stressed.

It is noted that an official declaration of war on May 9 would allow Putin, under Russian law, to mobilize reserve forces and call up conscripts. Other options considered by Western officials are the "timed" annexation of the Luhansk and Donetsk regions in Ukraine on May 9, a serious offensive on Odesa, or the declaration of supposedly full control over Mariupol.

As a reminder, the media earlier reported, citing the British side, that Russian President Vladimir Putin is using the date of May 9 to announce a mass mobilization of the population for a decisive strike against Ukraine.