The Russian army this week made its biggest 24-hour advance into Ukraine in over a year just days ahead of a meeting between US President Donald Trump and Russian President Vladimir Putin in Alaska, according to data from the US-based Institute for the Study of War.

The Russian army took or claimed 110 square kilometres (42.5 square miles) on August 12 compared to the previous day, according to AFP analysis of battlefield data from the Institute for the Study of War.

It was the biggest advance since late May 2024.

In recent months, Moscow has typically taken five or six days to progress at such a pace, although Russian advances have accelerated in recent weeks.

Russia – which currently has full or partial control over 19 percent of Ukrainian territory – said Wednesday 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.

"We are beginning the mandatory evacuation of families with children from the town of Bilozerske," Filashkin said, adding that around 1,150 children remained in the area impacted by the order.

Russia's offensive in eastern Ukraine was gaining speed and seizing ground Wednesday as European leaders held online talks with Trump ahead of his Alaska summit.

'New offensive operations'

Ukrainian President Volodymyr Zelensky acknowledged Tuesday that Russian troops had advanced by up to 10 kilometres (six miles) near the eastern coal mining town of Dobropillia, but said that Kyiv 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 said.

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".

"Putin is massing an army, his army is growing, he is stockpiling weapons, he is pulling the wool over our eyes," he said.

Pokrovsk in Russian sights ahead of Alaska summit

Russian forces on the ground in Ukraine have been closing in on a key territorial grab around the city of Pokrovsk, in the eastern Donbas region, which is part of Ukraine’s industrial heartland that Putin has long coveted.

Military analysts using open-source information to monitor the battles have said Ukraine's ability to fend off those advances could be critical: Losing Pokrovsk would hand Russia an important victory ahead of the summit and could complicate Ukrainian supply lines to the Donetsk region, where the Kremlin has focused the bulk of military efforts.

Meanwhile, Ukrainian forces struck an oil pumping station in Russia’s Bryansk region overnight on Wednesday, according to a statement from Ukraine’s General Staff.

Ukrainian drones struck the Unecha station which supplies the Russian army, the statement said, adding that damage and a large fire was reported in the area around the pumping station.

Unecha transports oil to two pipelines with an annual capacity to pump 60 million tons. The operation was carried out by units of the Unmanned Systems Forces of Ukraine’s army and the Main Intelligence Directorate of the Defense Ministry, the statement said.