As reported by Censor.NET citing BBC Ukraine, he said this in an interview to BBC Newsnight.
Poroshenko said it was quite clear for him that President Putin strives for global instability. Putin's goal, the president said, has been the same in Crimea 18 months ago, in the Donbas 15 months ago, and is now in Syria.
According to the Ukrainian president, Putin is trying to shatter the global security order due to economic problems and loss of support within his country.
As known, Moscow has been denying its participation in the conflict in Ukraine and presence of its career officers in the Donbas.