President Michael D Higgins has led tributes from politicians following the death of the former president of Finland Martti Ahtisaari, who was one of a number of international mediators in the Northern Ireland peace process.
Mr Ahtisaari, who was awarded the Nobel Peace Prize in 2008, died today aged 86.
Among his most notable achievements, Mr Ahtisaari helped reach peace accords related to Serbia's withdrawal from Kosovo in the late 1990s, Namibia's bid for independence in the 1980s, and autonomy for Aceh province in Indonesia in 2005.
In his work with the peace process in the late 1990s, he was tasked with monitoring the IRA's disarmament process.
President Higgins said Mr Ahtisaari's contribution to peace and reconciliation was not confined to Finland, but was "delivered to the whole world".
"The establishment of the Namibian state owes much to his efforts and he was to continue his efforts for peace in Kosovo, Cyprus, Aceh and of course Ireland," he said in a statement.
"Martti dedicated his life to the cause of peace.
"Importantly, he realised that peace is not something which can be simply wished for, rather it is something which can only be achieved through a process of engagement, negotiation and a shared commitment on each side to building a better, shared future for all those who have been in conflict.
"It was, importantly, something which he believed could be achieved in relation to all conflicts.
"In Ireland we will remain in Martti's debt for the important role which he played as a weapons inspector at a vital time in the peace process in Northern Ireland in the years following the signing of the Good Friday Agreement.
Former Sinn Féin president Gerry Adams said Mr Ahtisaari played a "crucial role in advancing the peace process" as one of a number of international mediators in Northern Ireland.
SDLP leader Colum Eastwood also paid tribute to Mr Ahtisaari, saying he "made a lasting contribution that will not be soon forgotten".
