President of Ukraine Volodymyr Zelensky claimed Friday that Russia has been "worried" by Ukraine's gains and that his country is now "advancing,” AFP reported.

"Russia is already wallowing in the mood of its defeat, already in a mood of hopelessness for itself", he added.

Earlier, Russian President Vladimir Putin said that Moscow was carrying out its military operation in Ukraine correctly.

"What is happening today is not pleasant. But all the same, (if Russia hadn't attacked in February) we would have been in the same situation, only the conditions would have been worse for us. So we're doing everything right," Putin told reporters at a press conference in Kazakhstan.