Russian President Vladimir Putin believes that the current election campaign in Ukraine has unacceptable forms, and if it continues to take place in such forms, the Russian authorities will not be able to recognize the legitimacy of Ukraine's upcoming presidential polls.

"The presidential race is proceeding in absolutely unacceptable forms. If it continues like this, we certainly will be unable to recognize the events that will follow May 25 [the Ukrainian presidential elections] as legitimate," Putin said during his annual Q&A session on Thursday.

"What legitimate elections are you talking about if candidates from the east [of Ukraine] are being beaten and pelted with ink all the time, and are not being allowed to meet their voters? What kind of election campaign are you talking about?" the Russian president said.