The UK is failing to offer credible answers to the "hard questions" Ireland and the EU are asking about the fate of the border post Brexit, the Foreign Minister Simon Coveney has said.
Mr Coveney rejected suggestions by Brexiteers that politicians in Dublin and Brussels are seeking to exploit the uncertainty over Northern Ireland's position to strengthen the EU's hand in the negotiations.
"We are certainly are not seeking to exploit anything," Mr Coveney said on a visit to Belfast.
"We are trying to protect a peace process that so many people from all backgrounds, unionist and nationalist, have worked so hard to create."
The Fine Gael minister added: "What's happening here is we are asking the hard questions and unfortunately we are not getting credible answers, which is why I think some people seem to be uncomfortable."
This week Democratic Unionist leader Arlene Foster accused Dublin and Brussels of acting "recklessly" in regard to Northern Ireland and claimed they were trying to use the North as a bargaining chip.
She was reacting to increasingly stark warnings from the EU side that a Brexit with Northern Ireland operating outside the rules of the customs union and single market would have dire consequences for the island's economy and the cross-border provisions of the 1998 Good Friday peace agreement.
Europe is calling for a solution that would see Northern Ireland continue to adhere to the EU's regulatory framework, to enable the retention of a free-flowing border.
This has angered unionists, who insist the North cannot be treated differently to the rest of the UK.
After addressing a Brexit-themed business breakfast hosted by the SDLP, Mr Coveney said he did not want to comment on the specific remarks made by Mrs Foster.
However, he stressed that the Irish government's position had been consistent throughout.
"I think what maybe has changed is that people are beginning to realise that the Irish government, and the indeed the EU negotiating team, are insisting on credible answers in terms of how we are going to deal with the Irish border issues in the future in the context of Northern Ireland and Britain leaving the EU," he said.
"And we are very serious on that because we do not want the relationship between Ireland and Britain, and in particular the relationships on the island of Ireland, to go backwards.
"And if there is regulatory divergence between the two jurisdictions on the island of Ireland, well then, in my view, that creates real problems in terms of the need for checks on the back of that regulatory divergence.
"So we have been consistent on that and I think the Irish government's position is very credible."