A former Ukrainian president says Russia is on course to be a "very, very big North Korea" unless it ditches Vladimir Putin.
Petro Poroshenko, who was in office between 2014 and 2019, said he had extensive dealings with the Russian president - but said the Russian leader never delivered on promises.
Mr Poroshenko said ordinary Russians would soon come to feel the effect of devastating sanctions, adding that he is "absolutely confident that Russia has the fate of a very, very big North Korea".
In an interview with Newsweek he said world leaders must commit to "de-Putinize Russia".
Comparing Russia to Kim Jong-un's regime in North Korea, he said that citizens have "no freedom, a dictatorship, full control of mass media, unhappy and poor people".
He said sanctions would be "disastrous" for the wider public in Russia, who have been "poisoned" by propaganda on TV.
But he continued: "They should pay the price for that.
"Learn the lessons, stop the aggression, give back Ukrainian soil, and then do their best to save Russia."
The former Ukrainian president urged leaders not to trust Putin.
He said: "Nothing he promised was really implemented. Don't be afraid of Putin. Putin goes as far as we allow him to go."
Mr Poroshenko said that the would either end in Ukrainian victory, which would be "the victory of the whole world", or with "capitulation of the whole world to Putin".
He added, however, that he does not believe the second scenario will occur.
Earlier today Vladimir Putin issued a chilling warning claiming Russia has successfully launched a huge intercontinental ballistic missile known as 'Satan-2'.
The Russian president bragged that the new Sarmat intercontinental ballistic missile would provide "food for thought" for anyone thinking of threatening Moscow.
He claimed no nation in the world is capable of stopping the newly-tested weapon, which experts believe is capable of firing more than 10 nuclear warheads at a time.
Russia's ministry of defence says the weapon was launched at the Plesetsk cosmodrome in the northwest of the country, and successfully hit targets in the far east.
The missile was seen emerging amid huge rocket flames and smoke from an underground silo in a video released by Moscow.
Putin, who is being investigated for war crimes committed by his forces in Ukraine, reportedly claimed the missile would "strengthen the combat potential of our armed forces".
