The head of the UN agency for children, Henrietta Fore, said on Tuesday she will step down because of her husband’s worsening health.
Ms Fore has been Unicef’s executive director since January 2018 and previously led US government development efforts as the head of the US Agency for International Development (USAID).
“With a heavy heart, I have informed the UN ... of my decision to step down as Unicef executive director in order to devote my energy to my husband’s serious health issue,” she posted on Twitter.
Ms Fore will remain in the job until a replacement is found.
"To serve the world’s children is both exhilarating and fascinating," she wrote.
"I am proud of the Unicef team. We have achieved remarkable accomplishments at an extraordinary time, and there is so much more to do."
UN spokesman Farhan Haq paid tribute to “her inspiring leadership of Unicef and for her service to improve the lives of children all around the world”.
Ms Fore also played a “critical role in the global response to Covid-19 and in reimagining education,” added the spokesman.
"As a result of her leadership, Unicef is now an organisation with a broader array of public and private sector partnerships and a bolder focus on achieving" world sustainability goals, Mr Haq said.
Unicef works in more than 190 countries and territories to save children’s lives, promote their rights and raise standards of education.
In the Middle East, the agency focuses on helping children in Syria, Libya, Yemen, the Palestinian territories and other areas where classrooms are frequently shuttered and young people are recruited into armed groups.