Bertie Ahern received a number of standing ovations during his speech
Bertie Ahern has told a joint session of the US Congress that centuries of strife in Ireland are over for good.
The invitation was issued to the Fianna Fáil leader in recognition of his work for the Northern Ireland peace process.
Mr Ahern received a number of standing ovations during his address, which came days before he steps down as taoiseach.
"After so many decades of conflict, I am so proud, Madam Speaker, to be the first Irish leader to inform the United States Congress Ireland is at peace."
He joined an elite group of five international statesmen who have been invited to speak to both houses in Washington.
'Dream come true'
Mr Ahern praised America's role in the Northern Ireland peace process.
"Our dream, and the dream of all of the friends of Ireland in America and across the world, has come true," he said.
"To you, to your predecessors and to all of the American leaders from both sides of the aisle who have travelled with us, we offer our heartfelt gratitude."
Mr Ahern spoke of Ireland's long-standing ties with the US, saying: "To be Irish is to be at home in America."
Mr Ahern is due to resign as taoiseach and leader of Fianna Fáil on Tuesday 6 May.
He was the first Irish leader to address MPs at the Palace of Westminster.
Accepting the invitation to Congress from Speaker of the House of Representatives Nancy Pelosi in February, Mr Ahern said he had been deeply honoured.
Other Irish statesmen also invited to make the Congress address included John Bruton in 1996, Garret FitzGerald in 1984 and Liam Cosgrave in 1976.
Presidents Eamon de Valera in 1964 and Sean T O'Ceallaigh in 1959 also addressed the House.