South Africa's last white president, Frederik Willem (FW) de Klerk, died on Thursday leaving a final apology via video for crimes against other ethnic groups during decades of apartheid.
"I, without qualification, apologise for the pain and the hurt and the indignity and the damage that apartheid has done to Black, Brown and Indians in South Africa," said de Klerk, who had previously expressed regret several times for the 1948-91 policy.
De Klerk died aged 85 after a battle with cancer.
He won praise worldwide for his role in scrapping apartheid and shared the Nobel Peace Prize with Mandela in 1993. The following year Mandela won South Africa's first multi-racial elections with his African National Congress (ANC).
"Allow me in this last message to share with you the fact that since the early 80s, my views changed completely. It was as if I had a conversion," de Klerk said in the video message released by his foundation hours after his death.
"And in my heart of hearts, I realized that apartheid was wrong. I realized that we had arrived at a place which was morally unjustifiable," he said, adding that action was then taken to negotiate and restore justice.
It was not immediately clear when the recording was made.
In the video, De Klerk also cautioned that South Africa faced many serious challenges, including what he called an undermining of the constitution.
President Cyril Ramaphosa paid tribute to de Klerk's role in South Africa's transition to democracy.
"He took the courageous decision (as president) to unban political parties, release political prisoners and enter into negotiations with the liberation movement amid severe pressure to the contrary from many in his political constituency," he said.
Mandela's foundation said de Klerk would "forever be linked to Nelson Mandela in the annals of South African history".
However, de Klerk's role in the transition from minority white rule remains controversial.
Many Blacks were angered by his failure to curb political violence in the turbulent years leading up to the 1994 elections, while right-wing white Afrikaners, who had long ruled the country under de Klerk's National Party, viewed him as a traitor to their causes of white supremacy and nationalism.
His complex legacy was reflected in the reactions of South Africans.
"The time he was president and the actions he did take part (in) to become a president are bad, very bad, sinful. It was the mass genocide of Black people," said Sihle Jwara, a student in Johannesburg.
"But at the same time you have to look at the actions that he did take to change the country."
De Klerk's foundation said he had died peacefully at his home in Cape Town on Thursday morning after a battle with mesothelioma, a cancer that affects the tissue lining the lungs.
His widow Elita and family will announce funeral arrangements in due course, it said.
The foundation of Archbishop Desmond Tutu, a veteran of the struggle against white minority rule and seen by many as the nation's moral conscience, said de Klerk had "occupied an historic but difficult space in South Africa".
He had seen the necessity of change and "demonstrated the will to act on it," it added.
John Steenhuisen, leader of the Democratic Alliance (DA), South Africa's second biggest party after the ANC, said de Klerk's success in bringing most white voters with him over the need to abolish apartheid helped ensure the transition was peaceful.
The DA is the main rival of the ANC but has struggled to shed its image as a party of white privilege.
Julius Malema, who heads the Marxist Economic Freedom Fighters (EFF), the country's third biggest political party, was much more critical, saying de Klerk should be referred to not as a "former president" but as a "former apartheid president".
Though long retired from active politics, de Klerk prompted anger among supporters of then President Jacob Zuma in 2016 when he accused them and their leader of seeking to advance their personal interests and of endangering democracy.
De Klerk again drew criticism last year when he told a national broadcaster that he did not believe apartheid was a crime against humanity, as declared by the United Nations.
The backlash forced de Klerk to withdraw from a virtual seminar in the United States, where he had been due to speak on minority rights and racism.