Ukrainian President Petro Poroshenko believes a referendum on the status of Donbas as part of Ukraine can be conducted.

"As to the self-government regime. If it requires constitutional changes, there is an appropriate constitutional procedure, which comprises a referendum. As a guarantor of the Constitution, I will ensure free expression of citizens' will so that all Ukrainians can say how the see the future of Donbas. However, I reiterate, it has to be part of Ukraine," he told a press conference in Kyiv on Friday.