Russia’s defence ministry said it had thwarted a “large-scale” Ukrainian assault in the eastern province of Donetsk on Sunday.
Ukraine has not commented on the report, which was made by defence ministry spokesman Igor Konashenkov on Monday.
He said Russian forces had killed 250 Ukrainian personnel, as well as destroying 16 tanks, three infantry fighting vehicles and 21 armoured combat vehicles – releasing a video which claimed to show some of the destroyed equipment.
“The enemy’s goal was to break through our defences in the most vulnerable, in its opinion, sector of the front,” said Mr Konashenkov. “The enemy did not achieve its tasks. It had no success.”
Announcing his direct involvement could be a response to criticism that Russia’s military brass has not been visible at the front or taken sufficient control or responsibility for military operations in Ukraine.
On Sunday, Ukrainian President Volodymyr Zelensky said at least 500 Ukrainian children have been killed in the war.
The United Nations says around 1,000 other Ukrainian children have been wounded and thousands of others have been forcibly deported to Russia.
“We must hold out and win this war!” he said. “All of Ukraine, all our people, all our children, must be free from the Russian terror!”
His comments came after Ukrainian authorities said a soldier returned to the central city of Dnipro to find his two-year-old daughter dead and his wife seriously wounded after a missile strike which left 25 people injured, including five children.
Russian drone and cruise missile strikes on Sunday targeted multiple areas of the country, including the capital, Kyiv.
The Ukrainian air force updated earlier figures and said air defences downed six of eight Shahed self-exploding drones and four of six cruise missiles fired.