LONDON (Reuters) - U.S. President Donald Trump said things would get very tough with the European Union unless the bloc shapes up over trade and NATO. "The European Union (is) treating the United States very, very unfairly on trade," Trump said at a meeting with the head of NATO in London. "The deficit for many, many years has been astronomical with the United States and Europe in their favour. I'm changing that and I'm changing it very rapidly."It's not right to be taken advantage of on NATO..