US President John Biden accused Russia of committing "horrific atrocities" after a missile strike on a train station in eastern Ukraine killed at least 50 people.
About 4,000 people, mostly women and children, gathered at the station, trying to escape an expected Russian advance east of the Donbass region.
And a missile attack on the station caused hundreds of wounded, in addition to the dead.
EU foreign policy chief Josep Borrell, who is visiting Ukraine, told the BBC that the attack on the Kramatorsk station was another attempt to break morale, after Russian forces failed to win the fight against the Ukrainian army
Russia denies targeting civilians, saying it is carrying out a "special military operation" to counter Ukrainian "nationalists" and "neo-Nazis