Ukraine's President Volodymyr Zelensky on Saturday pledged to retake more areas in the country's eastern Donbas region from Russian forces.
"Throughout this week, more Ukrainian flags have been raised in the Donbas. There will be even more in a week," he said in his evening address.
He spoke after Kyiv said its forces had begun moving into the key eastern town of Lyman and the defence ministry posted a video of soldiers holding up a yellow and blue Ukrainian flag there.
Russia's defence ministry said it had "withdrawn" troops from the town "to more favourable lines".
Zelensky told Russians they would be "killed one by one" as long as President Vladimir Putin, who ordered the invasion of Ukraine in February, remained in power.
"Until you all solve the problem with the one who started it all, who started this senseless war against Ukraine, you will be killed one by one," he said, calling the war "a historic mistake for Russia".