President Cyril Ramaphosa has extended his sincere condolences to the family of South Africa's Ambassador to Denmark, Zindziswa "Zindzi" Nobutho Mandela.
Aged 59, Mandela passed away in the early hours of Monday, in a Johannesburg hospital.
She was the youngest daughter of the late Nelson Mandela and Nomzamo Winnie Madikizela.
She had been posted to Denmark in 2015 and had been designated to become South Africa's Head of Mission in Monrovia, Liberia.
President Ramaphosa extended his condolences to the ambassador's immediate family, the Mandela family at large, friends of the late ambassador, and the Nelson Mandela Foundation.
"I offer my deep condolences to the Mandela family as we mourn the passing of a fearless political activist who was a leader in her own right. Our sadness is compounded by this loss being visited upon us just days before the world marks the birthday of the great Nelson Mandela.
"Zindzi Mandela was a household name nationally and internationally, who during our years of struggle brought home the inhumanity of the apartheid system and the unshakeable resolve of our fight for freedom.
"After our liberation she became an icon of the task we began of transforming our society and stepping into spaces and opportunities that had been denied to generations of South Africans. Her spirit joins Tata Madiba and Mama Winnie in a reunion of leaders to whom we owe our freedom," President Ramaphosa said.
The President also extended his condolences to the late ambassador's colleagues in the Department of International Relations and Cooperation, and the diplomatic community in South Africa and Denmark.
The late ambassador was raised in Soweto and educated in South Africa as well as in Swaziland. She spent many years involved in the liberation struggle and embraced roles in the arts, philanthropy and business.
In her political career, she served as the Deputy President of the Soweto Youth Congress. She was also a member of the Release Mandela Campaign, and was an underground operative of Umkhonto weSizwe.