Irish premier Leo Varadkar said the Belfast/Good Friday Agreement was about “defying historical expectations” – a leadership quality still needed in Northern Ireland.

The Taoiseach was applauded after telling a conference marking the 25th anniversary of the landmark peace deal that the people of Northern Ireland deserve a functioning Assembly.

“The challenges of today require Northern Ireland’s leaders to make the decisions that affect their constituents on the ground,” he told the event in Belfast.

“I believe that the Good Friday Agreement was about defying historical expectations.

“We need that kind of leadership still.”

Mr Varadkar said the accord “challenged our assumptions of what we once thought possible” and that, in the face of difficult compromises, “vision, leadership and optimism triumphed”.

He told those gathered at Queen’s University that leaders at the time “defied assumptions about what was possible”.

“They also defied those within their own communities … who would have preferred to stay mired in conflict to avoid concessions or compromises.

“They realised that, to see their way to a better future, they had to reject the divisions and differences that had kept Northern Ireland in what seemed an unresolvable impasse for many decades.

“These were not easy decisions to make and some paid a high personal and political price.”

Mr Varadkar paid tribute to the political leaders of 1998 for what they achieved, noting that many are now dead.

“I thank them from the bottom of my heart on behalf of my generation,” he said.

From left: Akshata Murty, Prime Minister Rishi Sunak, former US president Bill Clinton, Hillary Clinton and Taoiseach Leo Varadkar after the international conference to mark the 25th anniversary of the Belfast/Good Friday Agreement (Niall Carson/PA)

Mr Varadkar also committed to working closely with Prime Minister Rishi Sunak, saying the peace process is at its strongest when the Dublin and London governments work “hand in hand”.

“Both governments have an ongoing obligation to honour and implement the agreement and that is why I am so pleased to share a stage with Prime Minister Sunak,” he said.

“The peace process has always been at its strongest when the two governments have worked hand in hand, and Northern Ireland works best when the two governments work together with an agreed strategy.”

Mr Varadkar said the Windsor Framework will play “an essential role” in winning additional investment in Northern Ireland – and that the presence of US special envoy on economic affairs Joe Kennedy was “a reminder of the opportunities that lie ahead if we reach together”.

“The framework has been welcomed by the business community, which has expressed a desire to move forward and take advantage of the opportunities and certainty it offers,” he said.

“A prosperous Northern Ireland is a place in which people want to live, a place that people want to make work, a place where young people will stay and return to.”

Quoting John Hume, Mr Varadkar concluded: “Unionists and nationalists have at last taken the future in their hands, they have seized control of their history rather than letting history hold them in thrall.”

He added: “It is incumbent on Northern Ireland’s political leaders today to take the initiative.

“To see past ‘the shadow of the mountain behind’,” he said, referring to a metaphor used by David Trimble upon accepting the Nobel Peace Prize, along with Mr Hume, in 1998.

“To seize control of their history, to seize control of their destiny, and to lead their people into the future, and we as co-guarantors of the agreement will be here to help, every step of the way.”