Northern Ireland is variously described as a country, province, or region, which is part of the United Kingdom. Located in the northeast of the island of Ireland, Northern Ireland shares a border to the south and west with the Republic of Ireland. In 2011, its population was 1,810,863, constituting about 30% of the island's total population and about 3% of the UK's population.

The United States of America (USA), commonly known as the United States (U.S. or US) or America, is a country located primarily in North America, consisting of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles (9.8 million square kilometers), it is the world's third- or fourth-largest country by total area.