European Union Brexit negotiator Michel Barnier said he was ready to examine "realistic" proposals from Britain regarding its departure from the bloc, while reiterating the view that the previously agreed withdrawal deal was the best arrangement possible.
"We are ready to analyse #UK proposals that are realistic, operational & compatible with our principles. EU wants an orderly withdrawal but is ready for any outcome," Mr Barnier said in a tweet after meeting Dutch premier Mark Rutte.
Meanwhile, British Prime Minister Boris Johnson has played down the prospect of an imminent Brexit breakthrough, saying it would not be easy to persuade Brussels to shift its stance.
Mr Johnson, who held talks with Germany's Angela Merkel and France's Emmanuel Macron this week, said he was making progress but was "telling people not to hold their breath".
Mr Johnson wants the backstop - the contingency plan to prevent a hard border in Ireland - removed from the Withdrawal Agreement thrashed out with the European Union by predecessor Theresa May.
He acknowledged that the EU was "very hard over against it" and persuading Brussels to change would "take some time" - and the UK would have to prepare for the prospect of a no-deal Brexit.
Speaking to reporters in Devon, England, Mr Johnson said the "mood music" on his visits to Germany and France was "very good".
"They could see that we want a deal, they can see the problems with the backstop.
"Clearly, Angela Merkel thinks that the solutions can be found within 30 days - actually what she meant was if you can do it in two years, you can certainly do it in 30 days.
"But I want to caution everybody, OK? Because this is not going to be a cinch, this is not going to be easy. We will have to work very hard to get this thing done."
He insisted there were "lots of ways" to achieve frictionless trade at the border.
"But to persuade our EU friends and partners, who are very, very, very hard over against it, will take some time," he said.
"I'm afraid we will have to prepare to come out without an agreement and we can do that, we are very confident that we will be OK because we will have all sorts of preparations in place."
He added: "We are making progress but I am just telling people not to hold their breath, because I have seen the way these Brussels negotiations work."
Elsewhere, British Brexit Secretary Steve Barclay confirmed the UK will not nominate a new candidate for EU commissioner.
He said it would be a "distraction" to nominate someone for the post.
Mr Barclay added: "We are leaving the EU on October 31. As a departing member state we will not be involved in the new Commission so it would be a distraction to nominate a new commissioner.
"This is part of the UK's ongoing preparations for Brexit which allows us to focus on our future relationship with the EU while continuing to explore new opportunities with partners across the world."