Russia pummelled positions in the east of Ukraine yesterday, its defence ministry said, as it sought to encircle Ukrainian forces in the battle for Donbas and fend off a counteroffensive around the strategic Russian-controlled city of Izium.

The Nato secretary-general, meanwhile, told a meeting in Germany that Ukraine could win the war, calling for more military support and fast-track approval of Finland and Sweden's expected bids to join the alliance.

Ukraine has scored a series of...