The government has rejected claims it is unwilling to negotiate with the EU and wants talks to fail to allow a no-deal Brexit.
It comes after the EU said UK demands to remove the Irish backstop from Theresa May's deal were unacceptable.
EU negotiators told European diplomats there was currently no basis for "meaningful discussions" and talks were back where they were three years ago.
Downing Street said the EU needed to "change its stance".
The European Commission said on Tuesday morning it was willing to hold talks in the coming weeks by phone or in person, "should the UK wish to clarify its position in more detail".
A spokeswoman added the agreement negotiated by Mrs May - rejected three times by MPs - was the "best possible deal", and could not be re-opened.
Many opponents of Mrs May's deal cite concerns over the backstop - an insurance policy to prevent a hard border returning on the island of Ireland - which if implemented, would
see Northern Ireland staying aligned to some rules of the EU single market.
It would also involve a temporary single customs territory, effectively keeping the whole of the UK in the EU customs union. These arrangements would apply unless and until both
the EU and UK agreed they were no longer necessary.
A No 10 spokesperson said: "The prime minister wants to meet EU leaders and negotiate a new deal - one that abolishes the anti-democratic backstop.
"We will throw ourselves into the negotiations with the greatest energy and the spirit of friendship and we hope the EU will rethink its current refusal to make any changes to the
withdrawal agreement."
New Prime Minister Boris Johnson has pledged to leave the EU by the deadline of 31 October, with or without a deal.
BBC Brussels reporter Adam Fleming said the meeting on Sunday between officials and diplomats was a debrief from discussions last week between the EU, UK Brexit Secretary SteveBarclay and Mr Johnson's European envoy, David Frost.
A senior EU diplomat told the meeting a no-deal Brexit appeared to be the UK government's "central scenario", according to the Daily Telegraph and the Guardian.
"It was clear UK does not have another plan. No intention to negotiate, which would require a plan," the diplomat is reported to have said.
Mr Frost reiterated the prime minister's stance that the backstop element of Mrs May's plan must be abolished, and stressed that Mr Johnson's new ministers were not bound by commitments made by the previous government.
He also raised concerns about the UK's "divorce bill" and the proposed role of the European Court of Justice, the EU's top court, after Brexit.
'Continued dialogue'Further talks between the two sides have not been ruled out, and Adam Fleming said the G7 summit in France at the end of August could be the moment of truth - the point at
which a no-deal Brexit becomes inevitable.
Meanwhile, Mr Johnson is meeting his first foreign leader since entering Downing Street - Estonian Prime Minister Juri Ratas.
The country's Foreign Minister, Urmas Reinsalu, said earlier that while the "reality" was the withdrawal agreement - including the backstop - had been jointly agreed by EU member
states, there was still a need for continued dialogue in the coming weeks to avoid a no-deal Brexit.
He told BBC Radio 4's Today programme alternatives to the backstop could be discussed after the ratification of the withdrawal deal.
The EU is not optimistic about any agreement with the UK.
The message they are getting from Boris Johnson's team is that the UK is not going to sign another deal unless it involves getting rid of the backstop.
But the EU has been clear time and time again that it isn't going to do that - the backstop is an integral part of any withdrawal agreement and it has to stay.
So the conclusion of officials is there is no reason to get back round the table at the moment, for the simple reason that they don't think they can meet the conditions Boris Johnson has set.
