It comes as Vladimir Putin masses more than half a million troops on the frontline in a bid to overpower Ukraine's forces. The blitz, said to be the first stage of Russia’s summer offensive, is designed to stretch Ukraine’s already outnumbered defenders. He said: "The Russian forces have now expanded to 510,000 troops. "Disrupting Russian offensive plans is now our number one task," he said. Ukraine's armed forces said Moscow had achieved some “tactical successes” around the north-eastern city near the Russian border over the weekend.
