The Ukrainian army confirmed that fierce fighting broke out in the east and southeast of the country, saying that its forces had repelled dozens of Russian attacks there.
President Volodymyr Zelensky indicates that the first stages of the counterattack in these two regions are proceeding according to plan. But he expresses hope that progress will be faster in the two regions, which are the main theaters of his campaign to recapture territories captured by Russia.
Moscow also confirmed the occurrence of clashes, during which it said it was able to defend areas near the destroyed city of Bakhmut, where Ukraine says its forces are regaining territory.
Andriy Kovalyov, a spokesman for the Ukrainian General Staff, said Ukrainian forces had repelled a Russian advance, backed by artillery fire, near two towns north of Bakhmut, which were captured by Russian mercenary forces in late May.
The situation is unstable near Bakhmut, where Ukraine says it has made gains on the southern outskirts of the city, particularly the strategic village of Klishchevka.
Analysts say that liberating the village, which is located on higher ground, will enable Ukrainian forces to surround Russian forces in Bakhmut.
On Monday, Ukraine said it had taken control of the heights surrounding the village, enabling it to bomb targets in Bakhmut itself.
The Russian Defense Ministry said that its forces repelled nine Ukrainian attempts to advance in the eastern Donetsk region, one of them near Klishchevka.
In the south, Ukraine says it has recaptured a group of villages in the early stages of a campaign towards the Sea of Azov, aimed at cutting off the Russian land bridge linking eastern Ukraine to Crimea, which Moscow annexed in 2014.
Ukrainian General Oleksandr Tarnavsky said on Telegram that battles were raging throughout the strip, with troops repulsing 27 Russian attacks. He estimated Russian losses over 24 hours at several hundred dead and wounded.
Despite all the gains Ukraine has made in its counter-offensive, Russian forces still hold vast swaths of land after more than 500 days of war, some estimates suggest they represent 17 percent of Ukrainian territory.