The European Union's chief Brexit negotiator says reaching a deal for Britain's departure has become "more and more difficult".
The EU's Michel Barnier said a Brexit deal is still possible this week, although other EU members appeared sceptical this would happen.
The main sticking point is customs and security arrangements for the border between EU member Ireland and the British province of Northern Ireland, the only land frontier between the EU and the United Kingdom after Brexit.
"Even if an agreement has been difficult, more and more difficult, it's still possible this week," Mr Barnier told reporters in Luxembourg.
Irish Foreign Minister Simon Coveney(left) talks with the European Union's chief Brexit negotiator Michel Barnier (right). Source: EPA
"Reaching an agreement is still possible. Obviously, any agreement must work for all. The whole of the UK and the whole of the EU. Let me add also that it is high time to turn good intentions in a legal text."
Finland EU affairs minister Tytti Tuppurainen said the EU must prepare for a no-deal and another extension of the tortuous divorce process.
"All scenarios are open," she said.
European leaders are attending a summit in Luxembourg to discuss pushing back the current Brexit departure date of October 31.
British Prime Minister Boris Johnson during a debate at the House of Commons in London. Source: UK PARLIAMENTARY RECORDING UNIT
British Prime Minister Boris Johnson has pledged to take the United Kingdom out of the EU on that day whether or not a withdrawal agreement has been reached.
The British parliament has passed a law saying the country cannot leave without an agreement, and Mr Johnson has not explained how he can get around that.
German EU minister Michael Roth said he was not "quite sure if a deal is close".
"Nobody wants a hard, disorderly Brexit but that's what we're heading for," he said.
"There are still a few short days to reach a solution that's sensible for all concerned.
"The EU's conditions are very, very modest. The single market cannot be infringed and we want continued peace in Ireland and Northern Ireland."
British Brexit negotiator David Frost has started another round of negotiations with the EU's executive European Commission in Brussels.
The EU believes the only possible deal to be had at the summit is a return to keeping Northern Ireland in the EU's customs union, a proposal already rejected by Britain.
