The much feared Russian advance began in the early hours, soon after Putin announced he recognised Luhansk and Donetsk as independent states in a bombastic TV address.
Joe Biden and Boris Johnson condemned the move as an "invasion" and slapped sanctions on Russian banks and Putin's billionaire cronies.
Meanwhile, Russia announced it was pulling its diplomats out of Ukraine, claiming staff have 'received threats'.
Russian tanks have rolled into Donetsk and #Luhansk after Putin ordered 'peacekeepers' into the regions
Putin last night officially recognized the two areas of Ukraine as independent regions in a press conference
Biden late last night imposed sanctions against the two breakaway regions of Eastern Ukraine amid the move
But stopped short of issuing full-blown sanctions against Russia as Western allies deliberate their response
British authorities meanwhile have announced they will reveal the scale of their sanctions later today
UK Health Secretary Sajid Javid this morning declared on national television that 'the invasion has begun'
Prime Minister Boris Johnson confirmed a 'barrage of sanctions' will be revealed this afternoon
EU leaders are also set to meet this afternoon to discuss their approach to the crisis and determine sanctions