The Ukrainian troops had been withdrawn from the contested town of Debaltseve in eastern Ukraine, Ukrainian President Petro Poroshenko said on Wednesday.
Poroshenko said 80 percent of forces had been withdrawn from Debaltseve, while two more columns were expected to pull out.
He described the withdrawal as being "planned and organized", saying the troops had accomplished their mission. At the same time, he accused Russia of a "brutal violator" of the peace agreement signed in Minsk last week.
Poroshenko also denied reports that large numbers of Ukrainian were killed and hundreds of Kiev's troops captured. But in the nearby town of Artemivsk, officials say the hospitals and the morgue were full.