EU chief negotiator Michel Barnier said yesterday "no solution" has been found so far to break the deadlock over Brexit, a spokesman reported after the latest negotiations in Brussels.
Briefing the European Commission, the EU's executive arm, Barnier said the talks "have been difficult", spokesman Margaritis Schinas said following the four hours of negotiations on Tuesday.
Barnier informed the commissioners that "no solution has been identified at this point that is consistent with the withdrawal agreement," which the EU agreed with Prime Minister Theresa May in November.
Barnier said the discussions have nonetheless taken place in a "constructive atmosphere," speaking the day after he held the latest round of talks with UK attorney general Geoffrey Cox and Brexit minister Stephen Barclay.
Barnier confirmed the two sides were still stuck on the so-called "backstop," aimed at keeping open the border between EU member Ireland and British Northern Ireland.
The EU sees the provision in the withdrawal agreement as vital to preserving the peace process in Northern Ireland but London fears it will tie Britain indefinitely to an EU customs union.
The EU-British talks are aimed at helping May's government get the November divorce deal through parliament and avoiding Britain crashing out of the bloc on March 29 with out a deal.
Cox said he had put forward some "very reasonable proposals" during his talks in Brussels.
"Both sides have exchanged robust strong views and we're now facing the real discussions. Talks will be resuming soon," Cox told Sky News television from Brussels.
"These are very sensitive discussions, we're in to the meat of the matter now, we've put forward some proposals, very reasonable proposals," he said.
Cox's presence is seen as central as he will ultimately offer a legal opinion on the Brexit deal and the Irish backstop that could determine whether key pro-Brexit lawmakers will approve the withdrawal agreement.