Former US president Bill Clinton has described the Good Friday Agreement as a “work of surpassing genius”.
He was speaking at a conference in Belfast on the 20th anniversary of the 1998 accord.
Bill Clinton said: “The Good Friday Agreement is the work of genius that’s applicable if you care at all about preserving democracy.
“It called for real democracy, majority rule, minority rights, individual rights, the rule of law, the end of violence, shared political decision-making, shared economic benefits.
“The most interesting thing was, by creating a space for the identity and the interests and the value of all the people involved, in a framework that protected democracy and let future demographic, economic and political change take Northern Ireland wherever it would go.
“It was a work of surpassing genius.”
Bill Clinton will later receive the freedom of Belfast, alongside Senator George Mitchell, for their work in brokering the landmark agreement.
Opening the conference on Tuesday, Senator Mitchell hailed the "heroes and peacemakers" who helped end decades of violence in Northern Ireland.
“The real heroes of the Agreement were the people of Northern Ireland and their political leaders,” he said.
"The people supported the effort to achieve the Agreement and afterwards they voted overwhelmingly to ratify it.
"Their political leaders, in dangerous and difficult circumstances, after lifetimes devoted to conflict, summoned extraordinary courage and vision and reached agreement often at great risk to themselves, their families and their political careers.
"I ask you to join me in recognising the heroes and the peacemakers."