Russian Defence Minister Sergei Shoigu on Wednesday ordered his troops to withdraw from the west bank of the Dnipro River in the face of Ukrainian attacks near the southern city of Kherson.
The announcement marked one of Russia's most significant retreats and a potential turning point in the war, now nearing the end of its ninth month.
In televised comments, General Sergei Surovikin, in overall command of the war, said it was no longer possible to supply Kherson city. He said he proposed to take up defensive lines on the eastern bank of the river.
The news followed weeks of Ukrainian advances towards the city and a race by Russia to relocate more than 100,000 of its residents.
"We will save the lives of our soldiers and fighting capacity of our units. Keeping them on the right (western) bank is futile. Some of them can be used on other fronts," Surovikin said.