Secretary of State Karen Bradley has insisted that she and her cabinet colleagues are working hard to make sure that they can resolve the vexed issue of the Irish border.
Mrs Bradley also stressed that there would be no border in the Irish Sea after the UK leaves the EU.
"That's what we all want to achieve," she said today in Brussels, where she was meeting EU chief negotiator Michel Barnier.
"But obviously we need to put into legal text those matters that were agreed in the Joint Report and that's what we're working on."
The meeting came ahead of the European Council summit later this week.
The secretary of state also had a meeting with Ulster Unionist MEP Jim Nicholson, who again called on the British government to stand by its commitment that the constitutional integrity of the UK will not be diluted by any Brexit deal.
The Ulster Unionist MEP said it was clear that more work was required to resolve the issue of the Irish border.
"The European Commission is still unwilling to understand the unionist position in terms of its objection to the December backstop agreement as interpreted by the EU," he said.
"Indeed, this interpretation would itself represent a breach of the same Belfast Agreement the European Union has pledged to protect in Brexit talks."
Meanwhile, leading Tory Remainer Dominic Grieve has said that Theresa May's government would not accept new checks on goods moving between Northern Ireland and Britain – or the so-called 'border in the Irish Sea' scenario.
"A border down the Irish Sea is completely unacceptable and I think it’s abundantly clear that the government will never accept it," the Beacosnfield MP said.
Mr Grieve was speaking during a visit to the north last Thursday when he addressed an Ulster Unionist Party dinner.
Little over 24 hours earlier, the would-be rebel had voted with the Conservative government to ensure the Brexit bill passed through Westminster.
Mr Grieve predicted that Mrs May's government would fall if it tried to impose a border in the Irish Sea.
"Do bear in mind that even somebody like me, who is a Remainer, could never accept such an arrangement,” he told the News Letter.
