TAOISEACH Leo Varadkar has said European leaders are willing to grant a unique solution for Northern Ireland in Brexit negotiations.
In an address to business leaders in Derry city, the Fine Gael leader said EU nations understand peace on the island of Ireland is "young and still fragile".
However, he warned that "now more than ever we need an answer to the question of who we - and others in Europe - talk to in Belfast".
Mr Varadkar said there is "huge goodwill for Northern Ireland right across Europe".
"In my contacts with European presidents and prime ministers, I have received considerable support and understanding for the particular challenges we face," he said on Saturday.
"From Berlin to Brussels, they understand that Northern Ireland is unique, that the peace is young and still fragile, and are willing to make exceptions for Northern Ireland that would not be made for others."
Mr Varadkar said it is hoped that the ultimate outcome of the negotiations will be the "closest possible trade and customs relationship between the UK and the EU".
He added: "If this is ultimately not attainable, then we will seek a unique solution for Northern Ireland, reflecting its unique history and geography.
"A solution which does not undermine the constitutional settlement in any way, rather one that takes account of the realities on this island and builds on common regulatory approaches, frameworks and systems."
With talks to restore power-sharing at Stormont deadlocked for months, the taoiseach told Derry Chamber of Commerce that the best way to secure a unique solution for Northern Ireland is "to ask for it".
He said: "Now more than ever we need an answer to the question, of who we - and others in Europe - talk to in Belfast.
"Who will speak for Northern Ireland and her 1.8 million people?
"The clock is ticking and it is later than you think.
"We must protect what has been achieved in recent decades through the peace process and with the support and facilitation of the European Union."
The taoiseach's speech came in the wake of Brexit negotiators revealing that talks over the UK's divorce bill are stalling.
The discussions are stuck on phase one, with some progress reported on the issue of the Irish border and the Common Travel Area between the UK and Ireland.
Mr Varadkar said Stormont could play an important role in the Brexit negotiations, as there are mechanisms for the devolved administrations to be consulted and have a say on legislation from Westminster.
David Sterling, head of the Northern Ireland Civil Service, is to attend a Joint Ministerial Committee meeting in London today.
The formal group was set up to allow Scotland, Wales and Northern Ireland to have an input on exit negotiations but the Conservative government has faced claims it is not treating the devolved administrations with respect.
Damian Green, the prime minister's deputy, insisted he wanted the meeting to be "positive and constructive" but said it should recognise the "importance of preserving" the UK single market.
Scottish nationalists, however, will continue to push for the government to give Scotland a legal say on the exit process and drop plans to leave the EU's single market.
Mr Green said: "I remain committed to delivering a significant increase in the decision-making power of each devolved administration after we leave the European Union.
"I hope in our meeting on Monday we can agree on the principles for common frameworks that will deliver certainty and continuity to people living and doing business in the UK."
