In 2004, negotiations were held between the two governments, the DUP, and Sinn Féin, for an agreement to restore the institutions. The talks failed, but a document published by governments detailing the changes to the Belfast agreement was known as the “comprehensive agreement.” However, on 26 September 2005, it was announced that the Provisional Republican Army of Ireland had completely closed its arsenal of weapons and had “taken it out of service”. Nevertheless, many trade unionists, especially the DUP, remained skeptical. Among the loyalist paramilitaries, only the Loyalist Volunteer Force (LVF) had decommissioned all weapons.  Further negotiations took place in October 2006 and resulted in the St Andrews Agreement. The agreement was approved by voters across the island of Ireland in two referendums on 22 May 1998. In Northern Ireland, in the 1998 referendum on the Good Friday Agreement in Northern Ireland, voters were asked if they supported the multi-party agreement. In the Republic of Ireland, voters were asked whether they would allow the state to sign the agreement and authorize the necessary constitutional changes (nineteen constitutional amendments from Ireland) to facilitate it. The citizens of both countries had to approve the agreement to implement it.
Both views have been recognized as legitimate. For the first time, the Irish government agreed, in a binding international agreement, that Northern Ireland was part of the United Kingdom.  The Irish Constitution has also been amended to implicitly recognize Northern Ireland as part of the sovereign territory of the United Kingdom provided that the majority of the population of the island`s two jurisdictions has agreed to a unified Ireland. On the other hand, the language of the agreement reflects a change in the UK`s emphasis on the one-for-eu law to United Ireland.  The agreement therefore left open the question of future sovereignty over Northern Ireland.  The participants in the agreement were composed of two sovereign states (the United Kingdom and the Republic of Ireland), with armed forces and police forces involved in the riots. Two political parties, Sinn Féin and the Progressive Unionist Party (PUP), were linked to paramilitary organisations: the IRA (Commissional Irish Republican Army) and the Ulster Volunteer Force (UVF). The Ulster Democratic Party (UDP), associated with the Ulster Defence Association (UDA), had withdrawn from the talks three months earlier. The Good Friday Agreement (GFA) or the Belfast Agreement (irish: Comhaonté Aoine an Chéasta or Comhaonté Bhéal Feirste; Ulster-Scots: Guid Friday Greeance or Bilfawst Greeance) is a couple of agreements signed on 10 April 1998 that put an end to most of the violence of the Troubles, a political conflict in Northern Ireland that had erupted since the late 1960s. This was an important development in the Northern Ireland peace process in the 1990s. Northern Ireland`s current system of de-decentralized government is based on the agreement.
The agreement also created a number of institutions between Northern Ireland and the Republic of Ireland, as well as between the Republic of Ireland and the United Kingdom. Direct domination of London ended in Northern Ireland when power was formally transferred to the new Northern Ireland Assembly, the North-South Council and the Anglo-Irish Council when the opening decisions of the Anglo-Irish Agreement came into force on 2 December 1999.    Article 4, paragraph 2 of the Anglo-Irish Agreement (the agreement between the British and Irish governments on the implementation of the Belfast Agreement) required both governments to inquire in writing about compliance with the terms of entry into force of the Anglo-Irish Agreement; The latter is expected to come into effect as soon as both notifications are received.  The British government has agreed to participate in a televised ceremony at Iveagh House in Dublin, the Irish Foreign Office.