A Russian separatist leader in Ukraine’s Donbass region has admitted the situation is “very difficult” as Kyiv mounts a huge surprise attack. Ukraine is reported to have made far reaching progress in retaking territory invaded by Russia in the country’s easier Donbass regions. Unconfirmed reports have suggested that Kyiv’s troops mey have entered Donetsk Airport, on the outskirts of one the separatiss region’s biggest cities. An intelligence update said Russia had been “taken by surprise” buy the Ukrainian push.