PRESIDENT Michael D Higgins and Taoiseach Micheál Martin will be among the mourners at David Trimble's funeral.
The former first minister's funeral service will take place on Monday at Harmony Hill Presbyterian Church in Lisburn.
President Higgins' expected attendance comes eight months after his decision to decline an invitation to a church service in Armagh marking the centenary of Northern Ireland.
The leaders of Stormont's five largest parties are expected to join mourners also.
Confirmation that President Higgins will attend Lord Trimble's funeral came as former US Envoy to Northern Ireland Jim Lyons paid tribute to the former Ulster Unionist leader.
Mr Lyons, who was appointed by President Clinton, said he was saddened to learn of Lord Trimble’s passing.
He said the Tory peer "took the first and greatest political risk to make the Good Friday Agreement possible".
"He believed in unionism to his core but understood what was best for the people of Northern Ireland and their future," the former envoy said.
"He courageously put this above his own interests, a lesson from which we could all learn these days."
Mr Lyons said he welcomed Lord Trimble and Seamus Mallon to Denver, Colorado in 1998 as part of a post-accord trade delegation.
"It was while he was with us that he learned he had been awarded the Nobel Prize with John Hume," he said.
"He later came back to us in Denver to speak in a series of lectures featuring Nobel Peace laureates at Regis University—a Jesuit university in a which had also featured John Hume. As a board member of Regis, I was privileged to introduce them – each of them spoke to standing room only crowds and received standing ovations. They were inspirational."
