One of the Countries of the United Kingdom consist of Northern Ireland.  Who Does Northern Ireland co-operate with in some areas?
Northern Ireland: Northern Ireland (Irish: "Tuaisceart Éireann" ] ; Ulster-Scots: "Norlin Airlann ") is a part of the United Kingdom in the north-east of the island of Ireland, variously described as a country, province or region. Northern Ireland:  Northern Ireland co-operates with the Republic of Ireland in some areas, and the Agreement granted the Republic the ability to "put forward views and proposals" with "determined efforts to resolve disagreements between the two governments". Countries of the United Kingdom: The United Kingdom (UK) comprises four countries: England, Scotland, Wales and Northern Ireland.
Republic of Ireland