The Democratic Unionist Party (DUP) has said further work is required before it will back any fresh Brexit agreement.
Members of the party met Prime Minister Boris Johnson for the second night in a row amid speculation a deal is close.
Earlier, party leader Arlene Foster said the DUP would "stick with our principles" that NI "must remain" in the United Kingdom's customs union.
It comes after the Guardian said the UK has made further concessions over the issue of customs and the Irish border.
Downing Street has played down reports of an imminent deal with the EU.
In a statement following the 90-minute meeting, the DUP said: "We respect the fact negotiations are ongoing therefore cannot give a detailed commentary but it would be fair to indicate gaps remain and further work is required."
The DUP has consistently opposed any new customs checks between Northern Ireland and the rest of the United Kingdom, while the EU and the British government have both said there cannot be a hard border within the island of Ireland.
Asked earlier if the DUP had given any ground on customs checks, Mrs Foster told BBC News NI: "We are in a negotiation. I think it is right to give the negotiators space and time to do all of this.
"Everybody knows what our position is in relation to the constitutional and economic integrity of the UK.
"That is where we stand, we continue to stand there."
She added that the DUP had always said Northern Ireland must be "integrally within the UK" and dismissed some speculation around a Brexit deal as "so far off of the mark you can't see the mark anymore".
On Tuesday, EU negotiator Michel Barnier said there was a "narrow path" to a Brexit deal this week but the two sides would have to agree the details by the end of the day.
Taoiseach (Irish Prime Minister) Leo Varadkar said talks were "moving in the right direction" but gaps between the sides remained.
The UK is due to leave the EU at 23:00 GMT on 31 October.
Mr Barnier said there was a "narrow path" to be trod between the EU's objective of protecting the single market and Boris Johnson's goal of keeping Northern Ireland in the UK's customs territory.
The original Brexit deal struck between the EU and former Prime Minister Theresa May contained a clause known as the backstop, which would have seen the whole of the UK staying in the customs union for an indefinite period.
The DUP also opposed an earlier proposal from the EU that would have involved Northern Ireland alone remaining in the EU's customs union.
Mrs Foster said there was "no point reinventing that" and called for flexibility from the EU.