European Union leaders have failed to break the deadlock over the Irish border at a special Brexit summit.

They met in Brussels on Wednesday night, but have decided not enough progress has been made to call another summit in November.

The British Prime Minister Theresa May has also not ruled out an extra year of transition - which would allow more time to find a solution.

The EU27 agreed their common stance during a working dinner, prior to which they had been updated by Mrs May.

Mrs May spoke for around 15 to 20 minutes to other leaders, before departing for her own dinner separate from EU27 leaders at the UK's ambassador residence in Brussels.

Theresa May leaves the EU summit in Brussels after addressing leaders | Image: © European Union

The EU27 noted that "despite intensive negotiations, not enough progress has been achieved", an EU source revealed.

They added: "For now, EU27 is not planning to organise an extraordinary summit on Brexit in November."

It had previously been hoped this week's gathering of EU leaders would provide the breakthrough needed for Brexit talks to be wrapped up at a specially-convened summit next month.

However, with an impasse still remaining over the Irish border issue, the planned Brexit timeline has slipped again to mean all eyes will now turn to an already scheduled EU summit on December 13th and 14th.

Member states were also asked to work with even more vigour on planning for a "no-deal" Brexit, Dutch Prime Minister Mark Rutte revealed.

European Parliament President Antonio Tajani revealed Mrs May told EU leaders she will "keep under consideration" the possibility of extending the Brexit transition period - perhaps for another 12 months - although he added she offered a "neutral" opinion on such a scenario.

"She did not say anything in favour or against the three-year period," he said.

An extension to the Brexit transition period would allow more time for a future EU-UK trade agreement to be reached, with it suggested this could help de-escalate the current crisis over a backstop solution to the Irish border - the issue blocking progress in negotiations.

Taoiseach Leo Varadkar and British Prime Minister Theresa May hold talks in Brussels during an EU summit | Image: © European Union

Before she addressed EU leaders, Mrs May held a series of one-on-one meetings with Taoiseach Leo Varadkar, French President Emmanuel Macron, European Council President Donald Tusk and European Commission President Jean-Claude Juncker.

The tone of the meeting between Mr Varadkar and Mrs May was said to be positive and that they were getting somewhere.

Mr Varadkar said he has to trust the UK can deliver: "We have an alternative agreement that also assures us that there'll be no hard border on the island of Ireland.

"That's what we agreed in writing - the European Union and the United Kingdom - back in March.

"So this is not just now an issue of substance, it's an issue of trust."

On her arrival at the Brussels summit, Mrs May was upbeat about progress.

She told reporters: "We can achieve that deal, I believe a deal is achievable and now is the time to make it happen".

But the EU's chief Brexit negotiator Michel Barnier said progress will take time: "We will continue the work in the next weeks calmly and patiently - calmly and patiently".

Additional reporting: Sean Defoe in Brussels