Ukraine's president addressed the most powerful UN body after even more horrifying evidence of civilian massacres emerged in recently abandoned areas by Russian forces.
"They killed entire families, adults and children and tried to burn their bodies," Ukraine's President Volodymyr Zelensky said.
Ukrainian officials said the bodies of at least 410 civilians who had been withdrawn from Russian forces were found in cities around Kyiv. He also claims that a "torture chamber" was discovered in a town called Buka.
Zelensky said the civilian death toll in cities that had been freed from Russian control could actually be much higher.
Ukraine's president urged the United Nations to take more action.
"What is the purpose of our organization? Its purpose is to keep the peace," Zelensky said.
Zelensky said Russia was guilty of war crimes. He demanded to fix its accountability.
Western countries on Tuesday expelled dozens more diplomats from Moscow and weighed further sanctions as they expressed their disgust about a war crime.