Meghan Markle will join Prince Harry as he delivers a speech to the United Nations in New York next week.
The keynote address at the informal gathering of the UN General Assembly will take place on Monday July 18, which is Nelson Mandela Day.
Harry's speech is rumoured to touch upon the effects of climate change and world hunger, according to reports.
It will be the Duke and Duchess of Sussex's first joint public appearance since they were together at the Queen's Platinum Jubilee celebrations last month, where they kept a low profile.
The couple last appeared at the UN General Assembly in September 2021 but did not take part in the speeches in the assembly hall on that occasion.
A UN spokesman told the Daily Mail : "The South African Mission has confirmed the participation of the Duke and the Duchess at Monday's commemoration."
The late Diana, Princess of Wales, memorably met Mandela in South Africa in March 1997, just five months before she died in a car crash in Paris.
During his 2015 tour of South Africa, Harry visited the cell on Robben Island where Mandela was imprisoned for the first 18 of his 27 years in jail before the fall of apartheid.
And when he returned to the country with Meghan in 2019, the couple met Mandela's granddaughter Zamaswazi Dlamini-Mandela and his former cellmate Andrew Mlangeni.
They also met with the former South African president's widow Graça Machel who told them: "It's wonderful meeting you. I'm sure we're going to be working together in the future. I can feel the vibe."
The UN has marked Nelson Mandela Day since 2009. According to its website, people are encouraged to celebrate the occasion by making a difference in their community.
The strapline for this year's festivities is: "Do what you can, with what you have, where you are."
The UN's website says: "Everyone has the ability and the responsibility to change the world for the better! Mandela Day is an occasion for all to take action and inspire change."
