The 10th Secretary-General of the United Nations will be elected this year for a five-year term starting on January 1, 2027.

Here are the candidates who have so far competed to replace outgoing UN chief Antonio Guterres.

RAFAEL GROSSI

Rafael Grossi, a 65-year-old career diplomat from Argentina, has been an omnipresent and hyperactive director-general of the UN nuclear watchdog for the past six years.

While the International Atomic Energy Agency has long overseen Iran's nuclear program, Grossi led negotiations aimed at salvaging parts of a landmark nuclear deal between Tehran and major powers after President Donald Trump's decision to withdraw the United States from it in 2018. Grossi's critics argue that he has gone too far in trying to reach an agreement with Iran.

A father of eight and a polyglot who speaks English, Spanish, French and Italian, Grossi has raised both his own and the IAEA's profile with his intermediary diplomacy in international crises.

His most obvious success was the deployment of a small IAEA team to the Russian-occupied Zaporizhzhia nuclear power plant in Ukraine, after repeated trips along the front line during the Russia-Ukraine war.

He has tried to project the image of a man of action in this race, in which many diplomats see him as the favorite after years spent trying to keep the five permanent members of the UN Security Council - the United States, Russia, China, Britain and France - whose support is essential for the top job.

“These experiences have confirmed a conviction that I hold deeply: even in times of division, multilateral institutions can make a real and positive impact,” Grossi’s vision statement for the post reads.

REBECA GRYNSPANI

Rebecca Grynspan, 70, describes herself as a reform-minded multilateralist who has fought gender barriers and has had a lifelong faith in the UN and its commitment to peace, development and human rights.

A former vice president of Costa Rica who chairs the UN Conference on Trade and Development, Greenspan said she stepped down from her duties until September to avoid conflicts of interest during the campaign. Grossi has continued in his role at the IAEA during the campaign.

Born to parents who fled Europe after World War II, she connects her worldview directly to the origins of the UN and its role in international cooperation and conflict prevention.

If elected, Grynspan will become the first woman to serve as secretary-general. She said that while she had to make compromises between family life and public service at UNCTAD, being the first woman to lead shaped her leadership.

"I'm not expecting special treatment. I want equal treatment," she told Reuters.

Greenspan, an economist, describes herself as a "mature leader" who would lead a more agile UN through collaboration with other actors, while upholding its core values.

MICHELLE BACHELET

Michelle Bachelet, 74, is a two-time president of Chile and former UN High Commissioner for Human Rights, who also served from 2010 to 2013 as executive director of UN Women, an agency that promotes women's rights.

In March, Chile withdrew its support for Bachelet after a right-wing change in the country's leadership, but she said she would continue with the support of Brazil and Mexico.

The government of Chilean President Jose Antonio Castillo said its campaign lacked broad political consensus in the country and faced difficulties in the international arena.

Bachelet has faced criticism from American conservatives for her pro-choice stance on abortion, and in April, Washington's envoy to the UN, Mike Waltz, appeared to reject her bid, saying he shared a US senator's concerns about her suitability.

Republican Senator Pete Ricketts accused Bachelet of harshly criticizing the UN human rights chief in a 2022 report, failing to call China's actions against Uighur Muslims genocide, and also promoting abortion as a basic human right. Beijing has not stated its position on her candidacy.

MACKY SALL

Macky Sall, who was president of Senegal for 12 years until 2024, highlights his experience as head of state as a key asset for the role of secretary-general.

The 64-year-old geologist – the son of a peanut seller from a poor part of the West African country – completed major infrastructure projects during his tenure and has supported Africa's development.

Sall has stressed the need to support debt-ridden developing countries. He is calling for a review of the Security Council, in response to developing countries' demands for permanent seats on the UN's most powerful body.

"More than ever, a reinvented multilateralism remains the best way to respond to the challenges of a world in complete transformation," he said at X.

Sall, who speaks French more fluently than English, was nominated by Burundi. His candidacy has mixed support in Africa, with his homeland and Nigeria not backing him, according to diplomatic notes reviewed by Reuters.

If elected, he will be the third African secretary-general after Boutros Boutros-Ghali of Egypt and Kofi Annan of Ghana.