Samantha Power, the U.S. ambassador to the United Nations, pledged support to Ukraine and delivered a pep talk of sorts that encouraged Ukrainians to "demand change."
"America is clear-eyed when it comes to seeing the truth about Russia's destabilizing" actions in Ukraine, she said, adding that U.S. support for Ukrainians is "unwavering."
If Russia "continues to violate the rules upon which international peace and security" stands," Power said, then the United States will "raise the costs on Russia" and "rally other countries to do the same."
"Their silence in the face of Russian aggression will not placate Moscow," she said. "It will only embolden it."
Power spoke at Kiev's October Palace, a performing arts center. She stood behind a podium that had the U.S. State Department seal on it.
Power said that all too often, discussions about Ukraine are framed as dilemmas that pit the East versus the West or the U.S. versus Russia. "At best," she said, "the Ukrainian people get to choose one of these sides."
Instead, they should work to take control, but she acknowledged at length the "immense strain" they are suffering.
At least 6,350 people have been killed in violence "driven by Russians and the separatists," Power said. More than 1,000 are missing, more than 15,000 have been wounded, and the conflict has displaced at least 2 million people, she said.
She spoke about meeting a mother who had lost her 2-year-old child and husband in shelling and had fled her home in a van with her five other children. The vehicle's roof and sides had been blown out, Power said.
"The Ukrainian people are one of a kind, but the situation you find yourselves in is not," she said, adding that other countries around the world are threatened by a neighbor and are home to people who are powerless in the face of all-powerful leaders.
Those citizens "are watching you," she said.
Those leaders, she said, "are so rooting for you to fail."
Importance of reform in Ukraine
The U.S. diplomat earlier met with Ukrainian President Petro Poroshenko to discuss implementation of the Minsk agreement, which includes a ceasefire and other measures to resolve the crisis in eastern Ukraine.
"You cannot imagine how famous you are in Ukraine," Poroshenko joked at the beginning of the meeting, noting that a lot of people in Ukraine watched the broadcast of U.N. Security Council meetings on the Ukrainian issue.
Some international officials doubt that Russia is complying with the Minsk agreement.
The unresolved crisis in eastern Ukraine has been a focus of many top-level international discussions this week. Early in the week, the G7 group of industrialized countries said that sanctions against Russia could be stiffened if Russia does not observe the terms of the agreement.
And on Thursday, during a visit by Russian President Vladimir Putin
to Italy, he and Italian Prime Minister Matteo Renzi underscored their support for the agreement.