Former US president Bill Clinton will travel to Northern Ireland next month to mark the 20th anniversary of the Good Friday Agreement.
Mr Clinton will also journey to the Republic as part of a series of events to celebrate the historic peace accord of April 1998.
The ex-president and senator George Mitchell, the US diplomat who brokered the deal, will both receive the Freedom of Belfast on 10 April.
Lord Mayor of Belfast, councillor Nuala McAllister, said: "The contribution made by both president Bill Clinton and senator George J Mitchell to our peace process cannot be underestimated. Both have earned their place in our history as peacemakers, and both can be very proud of what they helped us to achieve."
On the same day the politicians will also attend a major peace building event at Queen's University in Belfast along with other major protagonists in the negotiations that largely ended three decades of sectarian conflict.
Other participants include former No 10 chief of staff Jonathan Powell, ex-taoiseach Bertie Ahern, former Sinn Féin leader Gerry Adams, former UUP leader and first minister David Trimble and former SDLP deputy first minister Seamus Mallon.
Former DUP leader and ex first minister Peter Robinson will also attend.
Queen's University's acting vice-chancellor, Professor James McElnay, said: "We are honoured and delighted to welcome President Clinton to Queen's University to mark the 20th anniversary of the Belfast / Good Friday Agreement.
"His role and influence on the peace process in Northern Ireland was pivotal to ensuring all parties reached agreement in April 1998. To have him back in Northern Ireland for this significant anniversary is a privilege."
On 9 April, both senator Mitchell and Mr Clinton will deliver speeches in Dublin.
Meanwhile, the former Northern Ireland Deputy First Minister Seamus Mallon has said the current stalemate does not signal the end of the Good Friday Agreement, but a new beginning.
He was speaking before taking part in a commemoration in Dublin of the 3,600 victims of the troubles.
Mr Mallon criticised the DUP who he said had diminished the process.
However, he said he was optimistic about the future because the peace and the structures are still there.
Seamus Mallon speaks of 'a new beginning' for Northern Ireland and the Good Friday Agreement pic.twitter.com/P5v6weGUf8
— RTÉ News (@rtenews) March 30, 2018
