United Nations Security Council Resolution 1999 is adopted, which admits South Sudan to member status of United Nations.

United Nations Security Council Resolution 1999 was adopted without a vote on 13 July 2011 after examining the application of the Republic of South Sudan for membership into the United Nations. The Council recommended to the General Assembly that South Sudan be admitted.

South Sudan, officially the Republic of South Sudan, is a landlocked country in East Africa. It is bordered on the north by Sudan; on the east by Ethiopia; on the south by the Democratic Republic of the Congo, Uganda and Kenya; and on the west by the Central African Republic. South Sudan's diverse landscape includes vast plains and plateaus, dry and tropical savannahs, inland floodplains, and forested mountains. The Nile River system is the defining physical feature of the country, running south to north across its center, which is dominated by a large swamp known as the Sudd. South Sudan has an estimated population of just over 12.7 million in 2024. Juba is the capital and largest city.