President Volodymyr Zelensky warned Ukrainians that Russia was throwing all its resources into a campaign to stop Kyiv's troops from pressing their counter offensive and a top general reported new progress on the southern front.
But Ukrainian military analysts suggested that things were not easy for Ukrainian forces in their bid to advance southward.
Ukraine has launched a counter offensive to take back swathes of land in eastern and southern Ukraine captured by Russian forces in their invasion launched in February 2022.
It has focused on capturing villages in the southeast in a drive towards the Sea of Azov and areas near the eastern city of Bakhmut, taken by Russian forces in May after months of battles.
Russian accounts said its forces had repelled Ukrainian attacks in eastern Donetsk region, including around Bakhmut.
"We must all understand very clearly, as clearly as possible, that Russian forces in our southern and eastern lands are doing everything they can in order to stop our soldiers," Zelensky said in his nightly video address after chairing a meeting with top commanders on Friday.
"And every thousand meters we advance, every success of every combat brigade deserves our gratitude."
Reuters was unable to verify battlefield reports.
'Systematically moving the enemy out of their positions'
General Oleksander Tarnavskyi, commander of Ukrainian forces in the south, said after the meeting that his troops were "systematically moving the enemy out of their positions."
Enemy losses over the past 24 hours were equivalent to at least 200, he wrote on Telegram.
"In the south, the situation is very difficult in advancing towards Berdiansk," military analyst Serhiy Hrabskyi told Ukrainian NV radio, referring to a port on the Sea of Azov. Ukrainian forces hope to cut off a land bridge Russian forces have established with the annexed Crimean peninsula.
"They are moving on the village of Robotyne. The enemy is offering resistance to stop our advance southward."
Russia's Defence Ministry, in its daily report, said its forces had repelled 16 Ukrainian attacks on the eastern front, including near the long-contested town of Maryinka and in the strategic village of Klishchiivka, on Bakhmut's southern fringe.