Taoiseach Micheal Martin has said he is "amused" at the speculation that Sinn Fein's victory in the Northern Ireland elections will prompt further debate about a border poll and a united Ireland.
He said it was not the "dominant" issue of the campaign.
It comes after Sinn Fein became the first nationalist or republican party to become the largest in the Northern Ireland Assembly with 27 seats, ahead of the DUP on 25.
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Sinn Fein can now nominate a first minister who will be the first from a nationalist or republican party.
Speaking on Sunday, party leader Mary Lou McDonald stepped up her call for preparations to start for a border poll on a united Ireland.
She told BBC Radio 4's The World This Weekend: "We have consistently been calling for the meeting of a citizens' assembly, Ireland-wide, to acknowledge and engage the change that is clearly happening in Ireland, to ensure that we have an inclusive and respectful forum where we can talk about change and, more importantly, plan for change Ireland-wide.
"We don't want to exclude anybody in the change that will happen... over the course of the next decade, be in no doubt about that."
She added: "The only one clear demand that I have made consistently for the last number of years is that preparation for constitutional change needed to start.
"Now the election itself that we've just been through demonstrates, I think quite dramatically, the change that's under way and we want that managed in an orderly, peaceful and democratic fashion."
Reacting to the comments on Monday, Mr Martin stressed his own support for Irish unity, but added: "That was not the mandate sought by Sinn Fein in the last three weeks.
"The whole campaign was on cost of living, on health and on housing.
"The border poll was nearly buried from its documentation and its manifesto and, (as) soon as the votes are counted, it is brought back into centre stage."
The Taoiseach also urged the DUP to form a power-sharing Executive alongside the other parties in Northern Ireland.
"I think everyone should reflect on the results. It is a significant result," he told RTE's Morning Ireland.
"All the parties, bar the Traditional Unionist Voice, focused on the bread-and-butter issues," he said.
"My sense is that the mandate they got was to take their Assembly seats."
"This was an election fought on current topical issues and, therefore, I think parties could lose out if they do not respond to what people said to them on the doorsteps."
The Fianna Fail leader also defended the approach taken by the EU towards the Northern Ireland Protocol.
He said: "I don't think the assessment that is coming from the British Government is a fair assessment of the EU's position. I think the European Union has been flexible, has demonstrated flexibility, but every time up to now that the European Union has demonstrated flexibility, it hasn't been reciprocated.
"And that has made the EU more cautious in terms of the discussions with the United Kingdom Government."
Mr Martin said he believes that, following the Assembly elections, agreement can be reached between the UK and the EU on the protocol.
"I think the moment is now for both the EU and the UK," he said.
"The British Government wants to bring this to a conclusion
"Any further sort of negative developments on this front will prove that Brexit isn't being done.
"I think all of us now have to have due regard to stability within the North, to the full workings of the institutions of the Good Friday Agreement."
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