Russia must face "just punishment" over its invasion of Ukraine, President Volodymyr Zelensky has told the UN General Assembly in New York.
He spoke on the same day Russian President Vladimir Putin called up 300,000 military reservists for duty, a move which prompted rare protests on the streets of Russia.
He condemned recently-announced plans in Russian-occupied areas of his country to hold so-called referendums on joining Russia - a plan denounced by Western leaders at the UN on Tuesday.
Mr Zelensky detailed allegations of war crimes in the city, including against one man said to have been castrated and murdered.
The word "punishment" cropped up some 15 times in Mr Zelensky's speech, and was the first of his five non-negotiable conditions for peace.
Russia must face consequences for its aggression, he said, through further sanctions against individuals and by the UN stripping Moscow of its powerful role as a permanent Security Council member.
He also called for Ukrainian lives to be protected, and for the country's internationally-recognised borders to be respected.
As his fourth and fifth conditions, he called for new security guarantees for Kyiv, and for the world to unite in calling out Moscow's armed aggression.
Sporting his signature green t-shirt, the Ukrainian leader thanked the 101 countries at the UN which voted to allow him to address the assembly in a video rather than in person.