The contest to choose the next Secretary-General of the United Nations has expanded, with Uganda's Olara Otunnu becoming the seventh official candidate seeking to lead the global body.

The United Nations on Saturday informed member states that Uganda had formally nominated the 75-year-old diplomat, who has held senior positions within the UN and previously contested Uganda's presidency.

The successful candidate will succeed Antonio Guterres, whose second five-year term ends on December 31, 2026. The new UN chief is expected to assume office on January 1, 2027.

Veteran diplomat with UN experience

Otunnu brings decades of diplomatic and international leadership experience to the race. From 1997 to 2005, he served as United Nations Under-Secretary-General and Special Representative for Children and Armed Conflict under then Secretary-General Kofi Annan. 

During his tenure, he led global efforts to protect children affected by war and advocated for stronger international measures against the recruitment of child soldiers.

Before that, Otunnu served as Uganda's Permanent Representative to the United Nations and briefly held the position of Foreign Minister.

Beyond diplomacy, he entered domestic politics and was the presidential candidate for the opposition Uganda People's Congress (UPC) in the 2011 general election, where he was defeated by longtime President Yoweri Museveni, who has been in power since 1986.

Seven candidates in the running

Otunnu joins six other candidates vying to become the UN's next Secretary-General:

Macky Sall (Senegal) 

Michelle Bachelet (Chile) 

Maria Fernanda Espinosa (Ecuador) 

Rafael Grossi (Argentina) 

Rebeca Grynspan (Costa Rica) 

Carolyn Rodrigues-Birkett (Guyana) 

The six previously announced candidates participated in a televised public dialogue on Thursday, outlining their visions for the future of the United Nations. 

The selection process now moves to the UN Security Council, where the 15-member body is scheduled to hold its first confidential "straw poll" on July 30.

During these informal secret ballots, council members indicate their level of support for each candidate. Several rounds of voting are typically held until one candidate secures the required nine votes while avoiding a veto from any of the Council's five permanent members, the United States, the United Kingdom, China, France, and Russia.

Once the Security Council agrees on a single nominee, it will recommend that candidate to the UN General Assembly, which will formally appoint the next Secretary-General.

The individual selected will become the 10th Secretary-General of the United Nations, taking office on January 1, 2027, for a renewable five-year term.

(With input from wires)