(CNN) Republican Rep. Liz Cheney of Wyoming on Sunday said Russia's missile strike on an eastern Ukraine railway station last week that killed dozens of civilians "clearly is genocide."
"I think that Europe needs to understand and grapple with the fact that you've got a genocidal campaign, the first kind of horrific genocidal campaign that we have seen, certainly in recent decades," she told CNN's Jake Tapper on "State of the Union."
Cheney added that European countries need to "understand that they're funding that genocidal campaign" through the purchase of oil and gas from Russia, and should place an embargo on Russian oil and gas.
At least 50 people, including five children, were killed and nearly 100 more were wounded on Friday from a Russian missile strike on a train station in Kramatorsk where they were waiting to evacuate, Ukrainian officials said Friday.
World leaders condemned the attack and the US State Department called it "yet another example of the Russian government's unjustified brutal war sowing senseless death and destruction in Ukraine."
Ukrainian President Volodymyr Zelensky has accused Russian forces of committing genocide in his country, pointing to the bombing of a maternity and children's hospital and apparent brutal executions of civilians in Bucha, Ukraine.
The Biden administration has accused Russia of war crimes and is supporting investigations into Russia's actions in Ukraine by helping document atrocities, but has stopped short of calling the killings a "genocide."
The United Nations defines genocide as "acts committed with the intent to destroy, in whole or in part, a national, ethnical, racial or religious group," including "killing members of the group," "causing serious bodily or mental harm to members of the group," and "deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part."
US national security adviser Jake Sullivan on Sunday downplayed the significance of "the label" of genocide in an interview on CNN's "State of the Union."
"In my opinion, the label is less important than the fact that these acts are cruel and criminal and wrong and evil, and need to be responded to decisively, and that is what we are doing," Sullivan said when pressed by Tapper on the Russian killing of civilians in Ukraine.
In a separate interview with ABC's "This Week," Sullivan said the administration views the attribution as a legal distinction.
"That is a determination that we work through systematically," he said. "There is a unit at the State Department that gathers evidence and then makes a legal analysis, because genocide is actually a legal determination."
Appearing on "State of the Union," Canadian Prime Minister Justin Trudeau told CNN that "it is clear that Putin is systematically targeting civilians," saying that's why Canada has supported an International Criminal Court investigation into war crimes.
Asked by Tapper if Russia's actions in Ukraine constitutes genocide, Trudeau said, "Those are the things that will be determined."
"Obviously, the messages we're seeing, the stories of what Russian soldiers are doing, not just the murder of civilians, but the systematic use of sexual violence and rape, to destabilize and have the greatest negative impact on Ukrainian people as possible is absolutely unforgivable and unacceptable," he added.