The UK government must intensify its engagement with EU negotiators to find legally watertight solutions for the Irish border, Ireland's deputy prime minister has said.
Simon Coveney was meeting EU chief Brexit negotiator Michel Barnier.
Mr Coveney said the Irish government wants EU leaders to be making "real decisions" in October.
He added time is tight to have a Brexit treaty ratified in time for the UK's withdrawal from the EU in March 2019.
Mr Barnier was briefing EU ministers on the state of talks with the UK ahead of a summit on Wednesday.
Before leaving for Brussels, Mr Coveney said he would "be making very clear our continued strong support for Michel Barnier, welcoming his approach on efforts to de-dramatise the backstop aimed at agreeing the text of the Protocol on Ireland and Northern Ireland".
"Time is short and it is important that the UK delivers on its commitments and engages constructively with the EU's proposed backstop," he said.
"The EU has been clear that without an agreement on a backstop, there cannot be an agreement on the Withdrawal Agreement."
The meeting comes ahead of a gathering of EU leaders in Salzburg on Wednesday, where UK Prime Minister Theresa May will urge her counterparts to get behind her government's Chequers plan for a Brexit deal.
Ahead of the summit, Brexit Secretary Dominic Raab said the UK will not accept a deal that includes a customs border in the Irish Sea.
In an interview with the Irish Times newspaper, Mr Raab said this was the position of Labour and Liberal Democrat MPs, not just Conservative and unionists.
"One of the few things I'm confident about is that parliament would not accept any deal that would threaten the integrity of the United Kingdom," Mr Raab told the paper.
"And actually I think it is far deeper than just the government or the government's relationship to the DUP, and I think there's evidence for that if you look at those votes and those debates."
It has been reported that EU President Donald Tusk will announce will propose an extra, extraordinary EU summit in November to deal with Brexit.