Former US president Bill Clinton has urged the people of Northern Ireland to finish the job of cementing peace.
The US statesman said great strides had been made in the region in the last two decades but said more work was needed to overcome issues outstanding from the past.
Addressing a crowd in the Guildhall Square in Londonderry, Mr Clinton said it was not for him to propose the way ahead.
He said politicians had “inspired the world” but more progress was needed.
“You have to finish the job,” he said. “That you free yourselves of the past so you can embrace it and be proud rather than be imprisoned by it.”
Mr Clinton began his day-long visit to Northern Ireland by crossing a symbolic peace bridge in Londonderry.
He walked across the footbridge linking the nationalist City side of the River Foyle with the unionist Waterside alongside former SDLP leader and Nobel Laureate John Hume and his wife Pat.
During his speech to a crowd in excess of 1,000, the former president paid tribute to Mr Hume’s efforts to secure peace.
But he said those still involved in the process needed to press on to overcome difficulties.
His comments come at a time when relations among parties in the region’s mandatory power-sharing executive at Stormont are at a low ebb, with a collective failure to resolve long-standing issues regarding parades, flags and, most crucially, the toxic legacy of the Troubles.
“This economy is coming back, we need to get this show on the road,” said Mr Clinton.
“So I implore you, for the sake of the young people, and all those who did so much, like John, for so long - finish the job.
“This is Ash Wednesday so permit me just one reference to scripture. Often at the funeral of good people the wonderful verse of scripture is cited from St Paul - ‘I have fought the good fight, I have kept the faith, I finished the course’.
“Well, you fought a good fight and I can look in your eyes and see you have kept the faith - you have not finished the course.”
Bringing his remarks to a close, Mr Clinton told the people of the city his heart would always be with them
“You have given me one more day in Derry I will never forget,” he said.
Mr Clinton was afforded an overwhelmingly positive response by the cheering crowds.
The only negative incident came when a lone dissenter briefly shouted out comments about the Iraq conflict.
Derry native Mr McGuinness was one of a number of politicians who attended the event in the Guildhall Square.
The Sinn Fein Assembly member said the visit of Mr Clinton was “hugely symbolic” and thanked the former president for engaging “emotionally and intellectually” in the peace process.
He also rejected any notion things had gone backwards politically since Mr Clinton’s last visit in 2010.
“I think President Clinton understands how this place has changed,” he said.
“If you cast your mind back to before he was President of the United States when there was conflict on our streets, when there were all sorts of incidents occurring, and (compare it to) what is happening now - we are an island of peace.”
He said the onus was on local politicians to conclude the work on the Haass process.
“We need to get back to the Haass template and we need to conclude the negotiations around that,” said the Deputy First Minister.
“Is there a prospect we can do that? I think there is every prospect if there is a will for us to do that.”
At the start of the event in the Guildhall Square, University of Ulster vice-chancellor Professor Richard Barnett announced that the institution had raised the £3 million required to secure a permanent endowed chair of peace studies.
The professorship at the university’s Magee campus in Derry will be named after Mr Hume and Tip O’Neill, the late speaker of the US House of Representatives who was a long-time advocate of the Northern Ireland peace process.
Donations from sources including the International Fund for Ireland and the American Ireland Fund helped the university raise the money to support the position.
The appointed professor will work out of UU’s International Conflict Research Institute - INCORE.
“The John Hume and Thomas P. O’Neill chair in peace will be a full-time professorship which will leave a lasting legacy of their work in peace-building, as well as their friendship,” said Mr Barnett.
“It will enable the university to build upon its unique role in training the next generation of peacemakers from around the world at its internationally-recognised International Conflict Research Institute, INCORE.”