Klitschko worries about possibility of Russia using tactical nuclear weapon on Kyiv.

Kyiv Mayor Vitalii Klitschko told CNN "there's no doubt" the capital is still Russia's main target in the war. The mayor warned residents coming back to the city to be cautious. "As mayor, I tell anyone, sorry, it's your personal risk, but we can't give you a guarantee … So long as there's war in Ukraine, we can't give the guarantee for any Ukrainian."