By John Chalmers and Marine Strauss BRUSSELS (Reuters) – The European Union is waiting to see the impact of a slew of sanctions on Russia before imposing any more, but it is working on further steps that could include targeting crypto-assets, officials said on Thursday. The president of the EU’s executive said the bloc would take additional steps against Moscow if the situation on the ground in Ukraine deteriorates further following Russia’s invasion of the country last week. “Our aim is to cut the Kremlin’s capacity to wage war on its neighbours,” European Commission President Ursula von der …