On Sunday Russian ballistic missiles pummeled the Ukrainian city of Sumy, resulting in a mass casualty event which was quickly condemned by the United States and European Union.

Trump's special envoy to Ukraine, retired lieutenant general Keith Kellogg, reacted by saying it "crosses any line of decency". He suggested the strikes targeted civilians. "As a former military leader, I understand targeting and this is wrong," Kellogg posted on X. He said there are "scores of civilian dead and wounded."

Ukrainian emergency authorities said the Sumy attack killed at least 34 people and wounded more than a hundred. Local officials said that among the dead were at least two children.