Naftogaz CEO Andriy Kobolev / Photo from UNIAN

"Gas is a very powerful weapon and Mr Putin is a very dangerous, experienced and efficient opponent," Mr Kobolev told BBC's HARDtalk.

There is a protracted dispute around Russia’s energy supply to Ukraine, which is also used as a transit route for natural gas exports to western Europe.

Read alsoTurkish Stream project to have negative consequences for Ukraine: Naftogaz CEOKobolev said that President Putin had a "long-lasting and successful track record" of using gas as weapon against Ukraine and that the task of Naftogaz was "to try to resist in this war and to win this war".