Russia is making rapid progress in its offensive in eastern Ukraine, seizing ground in a narrow but important section of the front line.
Analysis of battlefield data from the US-based Institute for the Study of War shows that Russian forces have made their biggest 24-hour advance in more than a year.
The head of the Donetsk region ordered civilians with children to evacuate from towns and villages under threat.
It comes as Ukrainian President Volodymyr Zelensky holds talks with European colleagues ahead of a meeting between the Russian and US presidents, Vladimir Putin and Donald Trump, on Friday.
Mr Zelensky has not been invited to the encounter, fuelling fears that his country could be forced into painful concessions.
Ukrainian soldiers in Kramatorsk, an eastern city about 20km from the front line, said they had low expectations for the diplomatic efforts.
"There have already been so many negotiations between the heads of state, but nothing is changing," said 21-year-old Dmytro. "If something changes for the better, I will be only happy."
The analysis of Institute for the Study of War data shows that the Russian army took or claimed 110sq/km of land yesterday compared to the previous day - the most since late May 2024.
In recent months, Moscow has typically taken five or six days to progress at such a pace, although its advances have accelerated in recent weeks.
President Zelensky acknowledged that Russian troops had advanced by up to 10km near the eastern coal mining town of Dobropillia, but said that his forces would soon "destroy them".
"We see that the Russian army is not preparing to end the war. On the contrary, they are making movements that indicate preparations for new offensive operations," he added.
Russia - which has full or partial control over 19% of Ukrainian territory - said that it had taken two villages close to Dobropillia.
Donetsk governor Vadym Filashkin said the region was beginning the mandatory evacuation of families with children from the town of Bilozerske and a dozen other settlements.
The Russian military also fired at least 49 drones and two ballistic missiles at Ukraine during the night, the Ukrainian air force said.
At least three people were killed in Russian artillery and drone attacks on the southern Kherson region, according to regional officials.
Artem, a 30-year-old serviceman in Kramatorsk, said the war would likely continue for "a long time".
"(President Vladimir) Putin is massing an army, his army is growing, he is stockpiling weapons, he is pulling the wool over our eyes," he said.
