STORY: Thomas-Greenfield said the UN was facing a "crisis of confidence" over the war in Ukraine.

"They (Russians) have not indicated that they have an interest in diplomacy. What they're interested in is continuing to raise this unprovoked war," she said.

Om Thursday, Russian President Vladimir Putin said he understood China's Xi Jinping had concerns about the crisis in Ukraine, a surprise acknowledgement of friction with Beijing over the war.

Thomas-Greenfield said she was not surprised, adding that "China has always spoken strongly about the importance of the sovereignty of nations."