Turning to the UK, where the Brexit talks step in a new chapter in 2018. While both sides are preparing for further discussion, the EU is still seeking a chance that Britain might stay in.

DONALD TUSK PRESIDENT, EUROPEAN COUNCIL "If the UK government sticks to its decision to leave, Brexit will become a reality, with all its negative consequences, in March next year, unless there is a change of heart among our British friends. Wasn't it David Davis himself who said: "If a democracy cannot change its mind, it ceases to be a democracy"? We, here on the continent, haven't had a change of heart. Our hearts are still open to you."

Leaders of the European Union institutions weighed in on a new British debate on whether to hold a second referendum on Brexit. Diplomats say those discussions reveal a firm line among the 27 on holding Britain to commitments to accepting continued obligations to the Union during the transition. But UK Prime Minister Theresa May's spokesman repeated her determination to follow through on Brexit.

The two-period Brexit talks will transition into the second period in 2018. The second period will mainly focus on debates over trade relations for both sides.