They have captured a string of villages near the border and subject larger towns, like the city of Sumy, to frequent shelling.

Sumy Regional Governor Oleh Hryhory said a 6 a.m. (0300 GMT) drone and missile attack killed three residents in or near Sumy and injured five.

But Zelenskiy, quoting Ukraine's top military commander, Oleksandr Syrskyi, said the Russian operation in the region "has been completely foiled by our forces."

"Fighting continues in the border areas of Sumy region, but the Russian grouping in the Sumy direction has lost its offensive capabilities as a result of the losses it has suffered," he wrote on Telegram.

Zelenskiy has reported successes in other operations in Sumy in recent weeks. He said Kyiv's forces were also actively repelling Russian troops in Donetsk and Zaporizhzhia, the two main areas on the front line.

Russia's Defence Ministry said its forces had captured a new village, Ternove, in Dnipropetrovsk region in the centre of Ukraine.

It was the second day in a row that Russia reported seizing a village in that region, adding to a list of several such localities in recent weeks. Ukraine has emphasised in public statements its efforts to keep Russians from gaining any ground there.

Ukraine's popular war blog DeepState, which uses open-source reports to track military positions, reported Russian gains near Ternove and at least one other village in the area.

But another military blogger reported that Ukrainian forces had taken back one village in the region from Russian troops.

(Reporting by Ron Popeski and Oleksandr Kozhukhar; Editing by Edmund Klamann)