Ukraine’s President Volodymyr Zelensky says that Russia is preparing its forces for a large-scale attack on Ukraine’s infrastructure. In his latest video address, Zelensky said he believed Moscow would focus on Ukraine’s energy sector first.Millions of Ukrainians have intermittently been left without electricity and water after Russian air strikes targeted vital infrastructure in recent weeks.Some 40% of Ukraine’s energy system has been damaged or destroyed by Russian attacks on power plants and lines.