Russian forces sought to encircle Ukrainian troops in twin eastern cities straddling a river as President Volodymyr Zelenskiy warned Moscow was seeking to destroy the industrial Donbas region where it has focused its attacks.
Russia is attempting to seize the separatist-claimed Donbas' two provinces, Donetsk and Luhansk, and trap Ukrainian forces in a pocket on the main eastern front.
Russian forces took control of three towns in the Donetsk region including Svitlodarsk, regional governor Pavlo Kyrylenko told a local affiliate of Radio Free Europe/Radio Liberty.
"The situation in Donbas is extremely difficult. All the remaining strength of the Russian army is now concentrated on this region," Zelenskiy said in a late-night address on Tuesday. "The occupiers want to destroy everything there."
Russia's defence ministry did not immediately respond to an emailed request for comment out-of-hours.
The easternmost part of the Ukrainian-held Donbas pocket, the city of Sievierodonetsk on the east bank of the Siverskiy Donets River and its twin Lysychansk on the west bank, have become the pivotal battlefield there. Russian forces were advancing from three directions to encircle them.
"The enemy has focused its efforts on carrying out an offensive in order to encircle Lysychansk and Sievierodonetsk," said Serhiy Gaidai, governor of Luhansk province, where the two cities are among the last territory still held by Ukraine.
Ukraine's military said it had repelled nine Russian attacks on Tuesday in the Donbas where Moscow's troops had killed at least 14 civilians, using aircraft, rocket launchers, artillery, tanks, mortars and missiles.
