Ukraine's military said it had made new advances on Wednesday in heavy fighting near the eastern city of Bakhmut, and that Russia was continuing to send in new units including paratroopers.
President Volodymyr Zelenskiy mentioned sustained Russian shelling in several regions, saying in a video address that these attacks showed the need to place further international pressure on Moscow.
The remarks on Bakhmut by military spokesman Serhiy Cherevatyi were the latest by Kyiv in the past week to indicate Russian forces have been pushed back in some areas.
"We are successfully conducting a defensive operation, counterattacking and during this day our units have penetrated up to 500 metres in some parts," he told Ukrainian television.
He said he saw no sign Russian forces were short of ammunition, contradicting statements by Yevgeny Prigozhin, head of the Wagner mercenary group spearheading the Bakhmut assault.
"The enemy is seeking to take over the city at will, striking with all systems and calibres," Cherevatyi said. "They are moving new units there (to Bakhmut), primarily paratroopers, in an attempt to achieve some kind of intermediate success."
Moscow sees Bakhmut, a city of about 70,000 before Russia's invasion, as a stepping stone towards capturing the rest of the eastern industrial Donbas region bordering Russia.
Ukrainian officials have signalled the advances around Bakhmut are not part of a broader counteroffensive planned by Kyiv to push back the Russian forces.
Moscow did not immediately comment on Cherevatyi's remarks although Russia's RIA Novosti news agency quoted the Russian Defence Ministry as saying its forces were continuing to fight to capture western parts of Bakhmut.
Prigozhin, in an audio statement, appeared to confirm Ukrainian forces now held an advantage in Bakhmut and he newly criticized Russian commanders.
"Despite the fact that the enemy has only a few percent of the territory in Bakhmut, surrounding the enemy does not appear to be possible," he said. "As a result of the enemy's advance ... Russian paratroops have taken up positions that are advantageous to the enemy."
Reuters was unable to verify the battlefield situation.
Ukrainian military analyst Oleksandr Musiyenko said the protracted battle resembled the Soviet army's defeat of Nazi troops in Stalingrad in 1943 after five months of fighting.
"Russian troops have lost the initiative on the flanks - our troops have cut off those flanks," Musiyenko told NV Radio.
