Ukraine's military says it has had success on one of the front lines in southeast Ukraine, as Western officials talk of a major thrust taking place.
In a video published by President Zelensky, Ukrainian troops said they had taken the village of Staromaiorske.
Earlier, Ukraine's military said it was "solidifying positions" it had reached in the same area, east of the city of Zaporizhzhia.
Ukraine has not confirmed that it has beefed up its counter-offensive.
But Russian President Vladimir Putin said Ukraine's attacks had "significantly" intensified.
He told reporters in St Petersburg they had had no success: "All counter-offensive attempts were stopped, and the enemy was pushed back with high casualties."
Russian-backed militia leader Aleksandr Khodakovsky contradicted Mr Putin, saying Ukraine had methodically shelled Staromaiorske for several days and made gains, holding on to the outskirts and pushing on.
Russian military blogger WarGonzo said the news was disturbing as Staromaiorske was a key Russian outpost on the front line in the south-eastern region of Zaporizhzhia.
Russia's war bloggers are considered an alternative source of information from the front line in the absence of official accounts.
Ukraine's counter-offensive began on a number of fronts last month but has seen very few clear gains so far. Kyiv's generals have warned that fast results are almost impossible because of Russia's fortified defensive lines and rows of minefields.
The man in charge of operations in the south, Gen Oleksandr Tarnavskyi, has told the BBC that "any defence can be broken but you need patience, time and skilful action".
Although there has so far been no word from Kyiv, unnamed US defence officials have told American outlets that a new push has begun in the Ukrainian counter-offensive.
The US-based Institute for the Study of War said an "intense frontal assault" had been launched towards Robotyne, to the south-east of Zaporzhhia city and some 10km (6 miles) south of the town of Orikhiv.
WarGonzo said Ukrainian forces were bombarding Russian forces on the northern and eastern outskirts of Robotyne, although that was not confirmed by Kyiv. The Russian defence ministry said Ukrainian attacks there had been repelled.
Ukraine's Defence Minister Hanna Maliar has spoken of a "gradual advance" in Ukraine's push towards the two cities of Melitopol and Berdyansk. Any advance towards either city would mark a decisive step in the military campaign.
If Ukraine's forces are able to make further progress in Robotyne, the next settlement to the south is Tokmak, on the road to Melitopol.
One area where Ukraine has said it is advancing is south of Bakhmut, the eastern city captured by Russian forces after a long and ferocious battle that reduced it to ruins.
Ms Maliar said Ukrainian forces were gradually moving forward and fighting was taking place in three villages on the front line directly south of the city. "The fighting is pretty harsh. Enemy fire is intense," she said.
In a separate development, Ukraine's parliament has voted to extend martial law for another 90 days, barring men of fighting age from leaving the country.
Martial law was imposed when Russia launched its full-scale invasion of Ukraine in February 2022. The vote also means parliamentary elections due in October will be delayed.