The US believes that the long-awaited Ukrainian counter-offensive will lead to Kiev regaining strategically important territory, US President Joe Biden's National Security Adviser Jake Sullivan told CNN journalist Fareed Zakaria, host of Fareed Zakaria GPS.

“Exactly how much, in what places, that will be up to developments on the ground as the Ukrainians get this counteroffensive underway,” Sullivan said.

“But we believe that the Ukrainians will meet with success in this counteroffensive,” he added.