'Final phase' Brexit talks to go on 'continuously'

"The negotiations are now entering the final stage," Barnier said, adding that from now on the UK and the EU will negotiate "continuously".

"We need to vitalise these talks and get issues out of technical discussions and into political resolution," Raab told reporters at a joint press conference after their meeting.

Negotiators are racing against the clock to find an agreement by October to give enough time for British and European lawmakers to approve the deal before the UK is due to leave the bloc next March.

One of the key stumbling blocks to a divorce deal remains how to solve the conundrum of the border on the island of Ireland, which will become the EU's new external border.

The UK and the EU have both promised to avoid a hard border on the island that could reignite sectarian conflicts in the region, but they need to agree on ways to police the line and inspect goods coming through.

The UK has rejected the EU's proposal to keep Northern Ireland in the EU's customs union and parts of the single market in order to protect the peace deal there.

But Britain has so far failed to come up with possible solutions that are workable or acceptable for the EU, which is keen to keep the internal market intact.

"We focused on what needs to be done," Barnier said of Tuesday's talks.

The border issue will be paramount to speed up the talks between now and the mid-October summit of EU leaders.

As the UK is getting ready on Thursday to publish a series of notes that should guide policies in case no deal is agreed, there is increasing chatter in Brussels of an extraordinary summit in November to seal the Brexit deal.

The very final moment for a deal to be struck could be the December meeting of EU leaders.

British prime minister Theresa May will also have a chance at an informal meeting of EU leaders in Salzburg, Austria, in mid-September to address the key issues.

"We can find common ground between the EU's principles and the UK's decision," Barnier said, adding that this needs to be done "well before the end of the year".