EU negotiator Michel Barnier warned Britain Monday to resolve the issue of its post-Brexit border with Ireland by a June summit, saying there had been little movement since leaders last met in March.
"I think nobody must underestimate the key rendezvous of June," France's Barnier told a security conference in Brussels. "Because as I have often said, the clock is ticking."
Barnier said the "two key points where there is a risk of failure" is the Irish issue, and the governance of any future Brexit deal, which Britain says must be out of the hands of the EU's top court.
The EU says Britain must agree to a workable solution to the question of how to avoid a hard border between EU member Ireland and the British province of Northern Ireland by the June 28-29 summit.
Brussels has set the tight timeline so that a full divorce agreement can be tabled by October, to give the European and British parliaments time to ratify it by the day Britain leaves the bloc on March 29, 2019.
During a meeting of ministers from the remaining EU 27 countries, "Mr Barnier informed us that since 23rd of March no significant progress has been made," Bulgarian Foreign Minister Ekaterina Zaharieva told reporters.
- Border control -
EU leaders agreed at the March summit on a post-Brexit transition period lasting until the end of 2020, during which Britain will remain in the EU's common market in exchange for following EU rules without any voting rights.
Barnier later said that there had been "a little, not very little progress" but warned that more was urgently needed.
London has committed to avoid a "hard border" with checkpoints between Northern Ireland and Ireland, which all sides agree is vital to maintaining the 1998 Good Friday peace accords.
But Britain has also said it will not enter into a customs union with the EU post-Brexit and has been urged to find a solution to reconcile the two positions.
The EU has suggested a "backstop" proposal, in which only Northern Ireland would stay in a customs union with the EU post-Brexit, but London says that would effectively create a border between Northern Ireland and the rest of the UK.
Barnier and the EU's foreign policy chief Federica Mogherini meanwhile both welcomed British proposals on a future security partnership with the EU.
The deal could include regular British-EU foreign policy talks, cooperation on military and aid missions, cooperation on defence projects and intelligence sharing, Barnier said.
But he reiterated that Britain could not participate in the EU's Galileo satellite programme, pointing out that London itself had approved EU rules saying that countries outside the bloc could not be involved.
Chief EU negotiator for Brexit, Michel Barnier said "the clock is ticking" for Britain to resolve its post-Brexit border with Ireland
London has committed to avoid a "hard border" with checkpoints between Northern Ireland and Ireland, which all sides agree is vital to maintaining the 1998 Good Friday peace accords