Taoiseach Micheál Martin warned that the next 72 hours will be critical for a Brexit deal as he urged both the UK and EU to "pull back from the brink" and let common sense prevail.
Mr Martin, speaking in Cork, stressed that the consequences of a no-deal Brexit would be hugely damaging for Ireland, the UK and the EU.
He welcomed the decision by Brussels and London to continue negotiating - but he said he was more hopeful than optimistic. "In my view it is extremely important and it is an imperative that both sides do everything they possibly can to avoid a no-deal Brexit because a no-deal Brexit would be very damaging all-round to the UK economy, to the Irish economy, to the EU economy, to workers and businesses who need certainty and who need clarity, and I think it is good that they are continuing with the talks.
"I do not underestimate the difficulties and challenges that face both sets of negotiators, but in my view where there is a will, there is a way.
"It is very important that they do everything they can to get a deal over the line.
"The real deadline, of course, is the end the year when the British Government and the British people leave the EU without a transition period, they leave the customs union and the single market, but obviously the next few days are crucial in terms of the practicalities around giving effect to any deal that would be arrived at."
He said the Republic would clearly lose out in a no-deal scenario.
"People may not realise but we are Britain's fifth largest market - Britain exports €38bn into Ireland - China comes next, about €30bn.
"And for us, of course, we export hugely into Britain as well and in the agri food industry we have a particular reliance on the UK market, so we are under no illusions about how damaging a no-deal Brexit would be to us and to Britain."
"I really hope that a deal can be got over the line, and in my view the fact that people are still talking is a good sign."
Foreign Affairs Minister Simon Coveney said both sides wanted a deal and were inching forward.
"It's a matter of days now," he said.
"A deal can be done. I think the last few days have been very difficult for both negotiating teams and there's enormous pressure on them to... find a way forward."