A late entry by a seasoned Emirati diplomat in the race to be the next secretary-general of the United Nations has shaken up a fraught process in which none of the other candidates has emerged as a clear favorite.

The United Arab Emirates this week formally nominated its former deputy foreign minister, Lana Zaki Nusseibeh, an eye-catching submission designed to capitalize the Middle Eastern nation’s efforts to establish itself as a trusted global mediator.

Nusseibeh, 47 years old, is one of the Emirates’ most experienced diplomats, spending much of her career at the U.N., including as her country’s ambassador to the international body for more than a decade. During that time, the U.A.E. transformed from a small player on the world stage to a formidable middle power that punches above its weight with huge resources for financial diplomacy and a small but professional military.

Her entrance “marks a pivot point” in the race, said Daniel Forti, head of U.N. affairs at International Crisis Group, noting she is well-known around the U.N. Jumping in after no leading candidate has emerged “is deliberate, and suggests her team believes she will not face similar roadblocks,” he said.

In response to questions from The Wall Street Journal, Nusseibeh said in a statement a number of governments approached her about vying for the job, in part to spur generational change. “I’ve built up over a decade a strong level of trust amongst major powers, but also middle powers who have become so influential today on the global stage,” Nusseibeh said.

Numerous U.N. member states have demanded a woman lead the institution for the first time when António Guterres, a former prime minister of Portugal, steps down at year-end after his decade as secretary-general.

Latin American leaders argue it is high time for the next secretary-general to come from their region and have promoted some of the strongest candidates in this year’s race, though none appeared to excite the wider membership.

A former vice president of Costa Rica, Rebeca Grynspan Mayufis, has prevailed in five of six nonbinding ballots held since July among U.N. Security Council members. But like other candidates she has also been discouraged by some key players, possibly including the U.S., during the complex and secret voting process.

Similarly, a Guyana nominee, Carolyn Rodrigues Birkett, who has served as its ambassador to the U.N. and senior diplomatic roles, has received support and faced detractors, coming slightly ahead of Argentine Rafael Mariano Grossi, director general of the International Atomic Energy Agency.

A problem for Nusseibeh could be the U.A.E.’s human rights record, both at home where it represses dissent and in wielding sizable economic clout abroad that critics say has undercut democracy and funded violent players in Sudan, Libya and Yemen. The U.A.E. rejects any characterization that it has supplied any party weapons in Sudan’s civil war. It also denies any role in Libya’s ongoing conflict.

Her push for the top job at the U.N. also comes amid high Middle East tension in the wake of attacks by the U.S. and Israel against Iran starting in February, and a response from Tehran that has included firing missiles at neighboring nations, including the U.A.E. across the Persian Gulf. Ultimately, a candidate needs backing by the U.S., China, Russia, France and the U.K., since each of the permanent five members of the Security Council holds veto power over the choice. None makes their preferences public, but polling results that have leaked suggest that all of the leading candidates have been met with at least some resistance from a P5 country.

No deadlines govern the U.N. membership’s choice of a secretary-general, but the process is running later than in past cycles.

Nusseibeh could benefit from divisions between the P5, such as a deepening U.S.-China rivalry, considering the U.A.E. can claim a strong working relationship with each one. Inside the U.A.E., a federation of monarchies governed largely by absolute rulers, Nusseibeh is known as one of a handful of technocrats who drive the country’s policies.

In a vision statement, Nusseibeh pledged “speaking frankly with every government and answering to none. There will be no exemptions for friends and no grudges against critics.”Nusseibeh would be the first secretary-general from a Gulf nation, and its first Muslim. She is also much younger than any other candidate in the field, but would be slightly older than the youngest-ever elected U.N. secretary-general, Sweden’s Dag Hammarskjöld, who took office at 47 in 1953.

She hails from an important Palestinian family in Jerusalem responsible for opening and closing the doors of the Church of the Holy Sepulchre, one of Christianity’s holiest sites. Her family moved to the U.A.E. in 1967 after the Israeli-Arab war, and her father, Zaki Nusseibeh, became an important adviser to Sheikh Zayed al-Nahyan, the Emirates’ founding father.

Among her biggest achievements as ambassador to the U.N. was helping steer passage of Resolution 2720 in December 2023, which helped accelerate humanitarian aid into Gaza during Israel’s war on Hamas after the militant group’s Oct. 7, 2023, attacks. News of her nomination produced immediate pushback from critics.

Ammar Mahmoud, a top U.N. diplomat for Sudan, criticized the choice of Nusseibeh considering what he described as a poor U.A.E. track record on human rights, including its support of Rapid Defense Forces in Darfur that the U.N. has called the world’s worst humanitarian crisis. “She is very much part of the propaganda machine that the U.A.E. is using to try to whitewash its image,” Mahmoud said, casting doubt that the Emirate would put her forward if it believed she would act independently of state interests.

In her statement to the Journal, Nusseibeh pointed to her decision to take a leave of absence from the U.A.E. government as evidence of her commitment to the U.N. “As U.N. secretary-general, if I were successful, my priority would be to continue spotlighting the desperate humanitarian situation in Sudan,” she said.

The U.N. secretary-general, a global mediator and administrator to a vast bureaucracy created after World War II, has limited power and an increasingly pinched budget.

Compounding the challenges for its next leader, the Trump administration has starved the U.N. of funding by accusing it of mismanagement and misalignment with U.S. interests, even as New York hosts its headquarters.

Nusseibeh appeared to nod toward Washington’s efforts to refocus the U.N. on its core mission by acknowledging in her vision statement that funding cuts are likely permanent. “A U.N. that responds by asking for more of the same will not be heard,” she said.

The uncertainty overshadowing the current selection process, which is taking longer than the previous two cycles, “reflects the consequences of an eroding international order and questions about the U.N.’s relevance in world affairs,” according to Forti. Along with political and financial pressures on the organization, he said, “This has rendered the job of secretary-general far less appealing but no less important.”