Speaking at a news conference in Brussels, Mr Tusk said the EU is “slowly turning the corner”.
“We are witnessing the return of the EU rather as a solution, not a problem.”
He continued: “The Brexit negotiations started three days ago. It is a most difficult process, for which the EU is well prepared.
“You can hear different predictions coming from different people about the possible outcome of these negotiations – hard Brexit, soft Brexit or no deal.
“Some of my British friends have even asked me whether Brexit could be reversed and whether I could imagine an outcome where the UK stays part of the EU.
“I told them that, in fact, the European Union was built on dreams that seemed impossible to achieve. So, who knows. You may say I’m a dreamer, but I’m not the only one.”
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