Ukraine has regained control of the entire Kharkiv region, reclaiming areas under Russian occupation since the opening days of Vladimir Putin’s invasion.
The state border service in Kyiv said it had liberated the city of Vovchansk, located close to the Russian border and one of the first territories seized by occupying forces.
In the space of a few days Ukrainian forces have regained control of more than 6,000 sq. km (4,300 sq. mi) of territory, including zones in the south of the country where a separate counter-offensive is ongoing to recapture the city of Kherson.
“In some areas of the front, our defenders reached the state border with the Russian Federation,” said Oleh Synyehubov, governor of the Kharkiv region.
A spokesperson for Ukrainian military intelligence said Russian troops were surrendering en masse as “they understand the hopelessness of their situation”. A Ukrainian presidential adviser said that the country was running out of space to accommodate prisoners of war having captured so many.
Western officials praised Ukraine’s “innovative and experimental” military strategy, which appears to have caught Russia off-guard and has seen fierce criticism of military leaders.
The US said that it had assisted Ukraine in wargaming potential counteroffensive strategies prior to the counter-offensive.
“We did do some modelling and some tabletop exercises,” Colin Kahl, the Pentagon’s policy chief, told the New York Times.
“That set of exercises suggested that certain avenues for a counteroffensive were likely to be more successful than others. We provided that advice, and then the Ukrainians internalized that and made their own decision.”