President Volodymyr Zelenskyy of Ukraine. Photo: Presidential Office of Ukraine

There will be no "sustainable peace" in Ukraine and Europe until control over the Russia-annexed Crimea and other Ukrainian regions is restored, Volodymyr Zelenskyy said on Friday.

Speaking via videolink at the opening of the Ambrosetti European House business forum in Italy, Mr Zelenskyy thanked the Italian government and people for their support, adding that now is "the time for strong decisions".

"We see Russia’s weakness and not its strength. With terror, they are trying to distract the world’s attention from understanding what Russia has become today. They are trying to hide their weakness," he said.

The Ukrainian president recalled the assassination of mercenary boss Yevgeny Prigozhin, claiming that "not all forces in Russia" are under the control of Russia’s Vladimir Putin.

"The murder of Prigozhin shows how weak his words were. It is impossible to negotiate with Putin because he cannot even keep his word," Mr Zelenskyy said.

He stressed that only the liberation of Ukrainian territory and the restoration of its territorial integrity can bring justice to the European region.

"Without Crimea, without Donbas and the occupied territories, there can be no sustainable peace in Ukraine, and therefore in Europe."