CHERNIHIV REGION, Ukraine (AP) — Russia and Ukraine began a major prisoner exchange Friday, swapping hundreds of soldiers and civilians in the first phase of an exchange that was a moment of cooperation in otherwise failed efforts to reach a ceasefire in the 3-year-old war.

President Donald Trump said on Friday that a major prisoner swap was just completed between Russia and Ukraine.

Many Russian soldiers say they would see a cease-fire along the current front lines as a failure, hinting at the nationalist discontent the Kremlin could face in accepting a cease-fire.