Vitali Klitschko has said he will fight for Ukraine after Russia declared war on its neighbour.
The former heavyweight world champion boxer’s country was attacked overnight as Vladimir Putin launched a "full-scale invasion".
So far 40 people have died and according to Oleksii Arestovich, an adviser to Ukrainian President Volodymyr Zelenskyy, dozens of people have been wounded.
Explosions have been heard across the country, in cities such as Kharkiv, Dnipro, Odesa and the capital city of Kyiv, of which Klitschko is the mayor.
The former WBO heavyweight champion issued a defiant statement and believes the people of Ukraine are ready to “defend our city", which he believes is under threat of a Russian takeover.
"I believe. I believe in Ukraine, I believe in my country and I believe in my people,” he told Good Morning Britain.
Asked if he would join civilians and soldiers in fighting Russian forces, Klitschko said: "I don't have another choice. I have to do that," before adding: "I will be fighting."
Vitali has held the roles of Mayor of Kyiv and head of the Kyiv City State Administration since 2014.
While many Ukrainian citizens are fearing for their safety, the politician tweeted out an encouraging message during a very worrying time.
“Be sure: Ukraine is strong!” he penned. “It has a strong capital #Kyiv, strong cities, villages and a strong solid and united people who value above all their independence, sovereignty and peace in Europe.
“Its WILL to exist is infinite. Glory to Ukraine!”
His younger brother Wladimir also took to social media to remind his followers of historic lessons.
“The world is watching how reckless and deadly imperialism is, not just for #Ukraine but the whole world,” Klitschko wrote. “Let history be a lesson to not be repeated.”
Around 10,000 troops moved into two breakaway areas of Ukraine - Donbas and Luhansk - that Putin recognised as independent states in the most aggressive move in recent times.
Addressing the conflict, UK Prime Minister Boris Johnson said: “Our mission is clear diplomatically, politically, eventually military, this hideous and barbaric venture of Vladimir Putin must end in failure. We cannot and will not just look away.”
Russia’s leader fired back an ominous warning to western countries that any interference will lead to "consequences you have never seen".
