STORYLINE:

The European Union's chief Brexit negotiator, Michel Barnier, says a deal with Britain might not come before November after talks hit an impasse over the weekend.

Speaking on the eve of an EU leaders' summit in Brussels, Barnier said several issues needed to be dealt with, including the future of the border between EU member Ireland and Northern Ireland, which is part of the United Kingdom.

"We are not there yet," he said.

More time is needed, he said, to agree an "overall agreement."

"We will use that time, calmly, with serious intent to find the overall deal in the coming weeks."

Barnier's comments have more or less put paid to any prospect of a decisive breakthrough at this week's summit.

Since the Brexit discussions began over 18 months ago, this October's summit had been earmarked as the most likely date for any agreement given the need to get necessary parliamentary approvals before Britain officially leaves the EU next March.