Ukraine has destroyed a strategically important bridge over the river Seym, as it continues its incursion into Russia's Kursk region.
Russian officials have been quoted as saying the operation near the town of Glushkovo has cut off part of the local district.
The bridge was used by the Kremlin to supply its troops and its destruction could hamper their efforts.
President Volodymyr Zelensky said Ukrainian troops were strengthening their positions in Kursk, and called the captured territories an exchange fund, implying they could be swapped for Ukrainian regions occupied by Moscow.
Now in its second week, this is Ukraine's deepest incursion into Russia since Moscow launched its full-scale invasion more than two years ago.
Ukraine’s surprise cross-border operation has resulted in more than 120,000 people fleeing to safety.
But amid Ukrainian claims of territorial gains, Kyiv has repeatedly maintained it does not wish to occupy Russia.
"Ukraine is not interested in occupying Russian territories," a senior aide to Ukrainian President Zelensky said on Friday.
Mykhailo Podolyak said one of the key objectives they wanted out of their incursion into Russia was to get Moscow to negotiate "on our own terms".
"In the Kursk region, we can clearly see how the military tool is being used objectively to persuade Russia to enter a fair negotiation process," he wrote on X, adding Kyiv has proven “effective means of coercion”.
The head of the Ukrainian military, Oleksandr Syrsky, said on Friday that the offensive had made further progress.
"The troops of the offensive group continue to fight and have advanced in some areas from one to three kilometres towards the enemy," he told President Zelensky in a video posted on social media.
Syrsky said he hoped to take "many prisoners" from a battle in the village of Mala Loknya, about 13km (8 miles) from the border.
As Ukraine's advance continues, officials in Russia's Belgorod region bordering Ukraine have said they will evacuate five villages starting on Monday.
"From 19 August, we are closing access to five settlements, removing residents and helping them bring out their property," Belgorod governor Vyacheslav Gladkov wrote on the Telegram social messaging app, naming small villages near the border.
However, as Ukraine moves further into western Russian territory, Russian forces are equally making gains in Ukraine’s east.
On Friday, Moscow said its troops had captured Serhiivka, the latest in a string of towns claimed by Russian troops in recent weeks.
The latest advances bring the Russians closer to the city of Pokrovsk, a vital logistics hub that sits on a main road for supplies to Ukrainian troops along the eastern front.
Pokrovsk lies north-west of the Russian-held Donetsk region, which has been under Ukrainian fire since Friday morning, leaving several civilians injured.
A message from the head of the city’s military administration, Sergiy Dobryak, on Thursday, urged people to evacuate as Russia was “rapidly approaching the outskirts".
