"To preserve the lives of our soldiers and the combat capability of our units, the Ukrainian defenders are withdrawing from the town," the army wrote in a statement.
It adds that the capacity of the Russian invasion force, both in number of soldiers and in equipment, was superior to the Ukrainian one.
At the same time, the Ukrainian military staff announces that Ukrainian forces are so close to the city that they can shell Russian forces inside Siversk.
Russia declared about two weeks ago that the city had been captured.
The town in the Donetsk region has been subjected to repeated and frequent shelling since the full-scale invasion began in February 2022. Russian invasion forces have lost many men and much material in attempts to gain terrain in the Donetsk area, where the fighting has been brutal and intense.
Siversk is located only about thirty kilometers east of the strategically important cities of Kramatorsk and Slovyansk, which are controlled by Ukraine.
Siversk is said to have had around 11,000 inhabitants before the invasion, and is a central location for mining, among other things, dolomite.
