Bridget A. Brink, the U.S. ambassador to Ukraine, is leaving office after three years.
"Ambassador Brink is stepping down. She's been the ambassador there for three years – that's a long time in a war zone. And frankly, the war has gone on for far too long," a State Department spokesperson said in a statement. "The real issue is whether the Russians and Ukrainians are ready to do what's necessary to end this war."
Brink, who is resigning from her post early, is leaving over personal and policy concerns, including the recent U.S. Agency for International Development layoffs, a source told CBS News.
Trump's administration has pushed for a quick end to the war launched by Russia in February 2022, but a lasting peace deal appears far from imminent.
Ukraine's top general has said a new Russian offensive push is underway in the northeast of the former Soviet satellite. Russia already controls a fifth of Ukrainian territory.
Information from Reuters was used in this report.