Speaking in Dublin, Bill Clinton has urged politicians in Northern Ireland to “take a breath” and keep working towards restoring the devolved powersharing Assembly.
The former US president also said that the ongoing negotiations around Brexit were hampering the restoration of Stormont, as politicians do not know what the terms of the withdrawal agreement will be.
Mr Clinton was making an address to mark the 50th anniversary of aid agency Concern, in Dublin, when he also spoke of how the 1998 Good Friday Agreement (GFA) was a model for “inclusive tribalism”.
Northern Ireland has been without a Government for 20 months following a row over a failed green energy scheme.
There have been a number of failed negotiations between Sinn Fein and the Democratic Unionists, however fresh talks are due within weeks.
Addressing the audience at Dublin Castle on Friday, Mr Clinton said: “If you were a Northern Irish politician you probably wouldn’t want to go into Government either if you didn’t know the details of Brexit and how it will affect Northern Ireland or how it will affect the relationship between Northern Ireland and the Republic, because how would you know what the terms of the agreement would be.
“There are still cranes up in Belfast and nobody wants to go back to the bad old days, so I think everybody should take a deep breath, and keep working.
“It’s almost impossible to solve real problems if there is no basic trust.
“If people are smart enough to realise that you didn’t have to have a document that would solve every problem, that would permit some solutions to emerge.
“The most important thing to me is that the Irish peace process and the work of Concern is rooted in both our common humanity and our notion of what I call inclusive tribalism.”
Mr Clinton first visited Northern Ireland in 1995, when he switched on the Christmas tree lights at Belfast City Hall, a little over a year after the paramilitary ceasefires, and when the peace process was still in its fledgling stages.
He added that Brexit has created uncertainty on the island of Ireland and how it will impact on the ongoing process of peace and reconciliation.
“Therefore it is a good time to be reminded of first principles and I think the example of the GFA is as good a place to start as any,” he added.
He said that what made the peace process work in Northern Ireland was people willing to compromise, as well as the persistence of ordinary people and the “courage of local leadership”.
“For me, the understanding of what the world should become starts with the Good Friday Accord and ends with the movie, the Black Panther.
“The Good Friday Accord worked first because it came from the bottom - people desperately wanted peace and the citizens weren’t just expressing their wants, they were doing things.
“I still don’t think the women’s groups involved in the Northern Ireland peace process have got the credit they deserve.”
Speaking about the legacy of Concern, he described it as Ireland at its best.
“It’s about inclusive tribalism, inclusive economics, inclusive social policy and personal empowerment.
“You can’t expect a pat on the back every day, you have to do it because it’s right, because you know it’s right and understand what you are dealing with.”
Mr Clinton was presented with a Dublin Gaelic football jersey by footballer Michael Darragh Macauley following their All-Ireland win on Sunday.