It comes following a meeting between Theresa May and European Commission president Jean-Claude Juncker on Wednesday, after which the pair said they are “seized of the tight timescale” facing them after holding “constructive” talks.
The PM had travelled to Brussels to seek legal assurances on the Northern Ireland Brexit backstop she believes are needed to secure parliamentary approval for her deal.
A joint statement issued after the meeting said: “The two leaders agreed that talks had been constructive and they urged their respective teams to continue to explore the options in a positive spirit.
“They will review progress again in the coming days, seized of the tight timescale and the historic significance of setting the EU and the UK on a path to a deep and unique future partnership.”
The statement said discussions had looked at “which guarantees could be given with regard to the backstop that underline once again its temporary nature and give the appropriate legal assurance to both sides”.
Talks also covered “the role alternative arrangements could play in replacing the backstop in future”.
The statement added: “Both reconfirmed their commitment to avoiding a hard border on the island of Ireland and to respect the integrity of the EU’s internal market and of the United Kingdom.”
The PM and Juncker agreed to talk again before the end of the month.
After the meeting, May said: “I have underlined the need for us to see legally binding changes to the backstop that ensure that it cannot be indefinite.
“That’s what is required if a deal is to pass the House of Commons.
“We have agreed that work to find a solution will continue at pace.
“Time is of the essence and it is in both our interests that when the UK leaves the EU it does so in an orderly way.
“So, we have made progress.”