BRUSSELS (AP) -- The European Union's Brexit negotiator urged the British government Tuesday to keep up the momentum in negotiations on leaving the bloc if it wants the talks to advance to a new phase in December.
"It's very important to maintain this constructive dynamic in the coming two months," Michel Barnier told reporters in Luxembourg.
Barnier held dinner talks Monday with British Prime Minister Theresa May and European Commission President Jean-Claude Juncker as London seeks to broaden the Brexit negotiations, around a year before the highly technical and complex talks must be completed to leave time for parliaments to endorse any agreement.
The EU says it will only discuss future relations with Britain once "sufficient progress" has been made on the divorce bill, the rights of citizens hit by Brexit and the status of the Northern Ireland-Ireland border. May believes these issues are deeply linked to future EU-U.K. relations, and that it all should be discussed as a package.
EU leaders are unlikely to broaden the talks at their two-day summit starting Thursday but might do so when they meet again in Brussels in December.
May and Juncker said in a statement late Monday that the Brexit talks "should accelerate over the months to come."
But it's unclear exactly what that means. Barnier is mindful that time is fast running out for a deal to be sealed before Britain leaves on March 29, 2019 and has already offered to speed things up. Britain too wants to move on, but the size of the divorce bill - estimated at anywhere between 60 and 100 billion euros ($70-120 billion) - remains the biggest hurdle.
"I am ready to accelerate," Barnier said again Tuesday, but he added that "it takes two to accelerate."
Asked what "accelerate" means, Britain's minister of state at the Department for Exiting the EU, Joyce Anelay said: "You put your foot on the gas in a car. You know you go faster. That's what it means."
In a draft statement prepared for this week's summit, the EU leaders say that in December they "will reassess the state of progress in the negotiations with a view to determining whether sufficient progress has been achieved."
If things go well, they will "adopt additional guidelines in relation to the framework for the future relationship and on possible transitional arrangements," according to the draft, seen by The Associated Press and which could be modified before, or at, the summit.