Tanaiste Eamon Gilmore has paid tribute to former US Senator George Mitchell after his resignation as Washington's Middle East envoy.
The Foreign Affairs Minister also expressed the Irish Government's deep appreciation for his tireless efforts in the pursuit of peace in the Middle East.
The 77-year-old international mediator helped broker the Northern Ireland peace deal.
Mr Gilmore said: "No-one has worked harder or with such dedication over the course of a long and distinguished career in public service to advance the cause of peace generally around the globe than George Mitchell.
"We in Ireland know only too well and with continuing gratitude what a superb mediator and architect of peace Senator Mitchell was in successfully chairing the negotiations which resulted in the Good Friday Agreement.
"While the attainment of a comprehensive peace agreement between Israel and the Palestinian people did not prove possible during Senator Mitchell's tenure, his determined efforts over the past two years have, I believe, advanced significantly the overall efforts to bring about such a peaceful and just settlement which is now more urgently needed than ever before."
Mr Mitchell was one of the first members of US President Barack Obama's foreign policy team to be named.
Mr Gilmore said his patience and committed approach will continue to inspire all of those who are committed to advancing the cause of peace in the Middle East.
"It should encourage a redoubling of efforts to achieve the final honourable peace settlement between Israel and its Arab neighbours which we all know is attainable with the necessary political will," he added.
Mr Obama accepted the resignation from a man he called "a tireless advocate for peace". David Hale, Mr Mitchell's deputy, will serve as acting envoy.