Sinn Féin President Gerry Adams has said a new approach is needed to persuade unionists of the benefits of a united Ireland.
He was speaking at a conference on the constitutional question in Belfast on Saturday.
Mr Adams predicted that there could be a vote in favour of ending partition within a "few short years" - but only if unionist opposition was ‘unlocked’.
He explained: “We need a new approach, one which unlocks unionist opposition to a new Ireland by reminding them of their historic place here and of the positive contribution they have made to society on this island.
"Instead of concentrating on the negative aspects of our four centuries of shared history I suggest that we embrace the areas of agreement and of co-operation; of good neighbourliness and the common good.
"A truly united Ireland will emerge from the reconciliation of the people of this island based on equality."
Gerry Adams said Brexit, the results of recent elections and the census conclusions from 2011, are evidence of a shifting demographic and political dynamic in local politics.
He called for advocates of unification - both politicians and within society - to "consciously address the genuine fears and concerns of unionists in a meaningful way".
Mr Adams added that the “future role of the Orange” would need to be addressed and invited the institution's leaders to meet with Sinn Féin.
He said there is a need to “look at what unionists mean by their sense of Britishness and be willing to explore and to be open to new concepts”.
Gerry Adams went on: "Hopefully as part of this process they too will be willing to explore what is meant by Irishness."