Russian troops have been ordered to leave Kherson, a key city in southern Ukraine.
General Sergei Surovikin stated on television that it is no longer possible to supply Kherson and other parts of the Dnipro River’s west bank.
He said: “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.”
Russia’s defence minister Sergei Shoigu responded by saying: “I agree with your conclusions and proposals.
“Proceed with the withdrawal of troops and take all measures to transfer forces across the river.”
The announcement marks one of Russia’s most significant retreats – Kherson city was seized by Russia early in the war and is the only regional capital the country has taken during the conflict, which is almost nine months old.
Mikhailo Podolyak, an adviser to Ukraine’s president Volodymyr Zelenskyy, said: “Ukraine does not pay attention to Russian statements – words and actions differ.”
Kherson region was annexed in September, along with three other parts of Ukraine – Luhansk, Donetsk and Zaporizhzhia.
Mr Zelenskyy has said a number of times that the return of all occupied territory is a condition for any peace talks with Russia.
But Russia is unlikely to relinquish its claim to the four regions, or to Crimea, which it took in 2014.