The ball is in the UK's court to address problems the EU sees in the new Brexit proposal, and not the other way around, a spokeswoman for the European Commission has said.
"As we have said there are problematic points in the United Kingdom's proposal and further work is needed. But that work needs to be done by the United Kingdom and not the other way around," spokeswoman Natasha Bertaud told a media briefing.
While the EU has cautiously said the document contained some progress on the sticking point of Northern Ireland it also had problems.
Those are understood to focus on the reliance on UK good will and untested technology to prevent a border springing up anew between the British province and EU member Ireland, and a provision periodically allowing part of the Northern Ireland assembly to veto the agreement.
Mr Johnson's ministers have suggested that, having handed over the Brexit proposal, the ball was now in the EU's court.
But the spokeswoman said "we would disagree."
She added: "We would remind you that it's the UK leaving the European Union and not the European Union leaving the UK and we are doing everything in our power to ensure that exit is on an orderly basis.
"And we are willing to engage constructively with our counterparts. But we are not going to be the ones left holding the bag, the ball or any other kind of object."
The European Parliament's Brexit steering group will today publish a detailed response to the new Brexit plan put to them by Boris Johnson yesterday.
European Union negotiators say they have already identified serious problems with the solutions tabled by the UK Prime Minister.
They say it does not solve the issue of the Irish border, and so threatens both the peace process and the functioning of the EU single market.
They also say it lacks detail about how the UK would ensure any necessary checks happen - even away from the border.
European Commission President Jean-Claude Juncker will speak to Taoiseach Leo Varadkar later today.
The commission said the phone call follows yesterday's conversation between Mr Juncker and Boris Johnson on the prime minister's Brexit plan
Meanwhile, asked about the EU's border concerns this morning, Brexit Secretary Stephen Barclay told BBC Breakfast that European Commission President Jean-Claude Juncker is "not wedded to the backstop", adding that both sides recognise that the best way forward is to reach a deal.
"The key issue is that there is a clear commitment from the UK Government to the Belfast Good Friday Agreement," Mr Barclay said.
"Within these proposals there's no infrastructure at the border in Northern Ireland and that's a key issue for the Irish Government.
"But if there's no deal then obviously the Irish Government will themselves have to put in place arrangements, so it's far better that we do this in partnership with a deal and that is what the paper sets out."
Earlier, asked how goods will be checked, Mr Barclay told ITV's Good Morning Britain the proposals clearly reduce the need for checks, adding that coming out of a customs union inevitably requires there to be some customs checks.
"And those will be done at premises, and we've set out in the paper all the detail as to how that would work," he said.
He added that after speaking to EU chief negotiator Michel Barnier it was clear that the EU recognises these as a "serious set of proposals".
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Also speaking about the Brexit proposals, shadow secretary of state for Northern Ireland Tony Lloyd said the plan tabled by Mr Johnson is not compatible with the Good Friday Agreement.
Mr Lloyd told the BBC Radio 4's Today programme that the issues at stake are not technical.
"These are issues about real people, real people and their lives," he said, adding: "I can't believe that this is a point on which Brussels or Dublin would be prepared to compromise because it's so fundamental" .
Earlier, Trevor Lockhart, group chief executive at Fane Valley Co-op, an agri-food business based in Moira, Northern Ireland, told the same programme the interests of businesses in the region have been sacrificed.
Mr Lockhart said the UK backstop delivered economically but clearly did not work politically. As a result, he added, in the pursuit of getting a political solution the interests of businesses in Northern Ireland to some extent have now been sacrificed
"It's ultimately a balance between what works politically and what works economically," he said.
"But it ultimately is important that we get a deal, because the threat of a no-deal to Northern Ireland businesses is the worst risk of all."
Mr Lockhart reiterated his hope for constructive engagement by all parties around the proposed solutions, adding: "But as they currently stand, the Government proposals don't represent a final destination for Northern Ireland business."