De Klerk died after a battle against cancer at his home in the Fresnaye area of Cape Town, a spokesman for the F.W. de Klerk Foundation confirmed on Thursday.
De Klerk was a controversial figure in South Africa where many blamed him for violence against Black South Africans and anti-apartheid activists during his time in power, while some white South Africans saw his efforts to end apartheid as a betrayal.
It was de Klerk who in a speech to South Africa's parliament on Feb. 2, 1990, announced that Mandela would be released from prison after 27 years. The announcement electrified a country that for decades had been scorned and sanctioned by much of the world for its brutal system of racial discrimination known as apartheid.
With South Africa's isolation deepening and its once-solid economy deteriorating, de Klerk, who had been elected president just five months earlier, also announced in the same speech the lifting of a ban on the African National Congress and other anti-apartheid political groups.
Amid gasps, several members of parliament members left the chamber as he spoke.
Nine days later, Mandela walked free.
Four years after that, Mandela was elected the country's first Black president as Black South Africans voted for the first time.
By then, de Klerk and Mandela had been awarded the Nobel Peace Prize in 1993 for their often-tense cooperation in moving South Africa away from institutionalized racism and toward democracy.
The country would be, de Klerk told the media after his fateful speech, "a new South Africa." But Mandela's release was just the beginning of intense political negotiations on the way forward. Power would shift. A new constitution would be written. Ways of life would be upended.
"There is an element of uncertainty, obviously, with regard to everything which lies in the future," de Klerk calmly told reporters on Feb. 10, 1990, after announcing that Mandela would be released the following day.
The toll of the transition was high. As de Klerk said in his Nobel lecture in December 1993, more than 3,000 died in political violence in South Africa that year alone. As he reminded his Nobel audience, he and fellow laureate Mandela remained political opponents, with strong disagreements. But they would move forward "because there is no other road to peace and prosperity for the people of our country."
After Mandela became president, de Klerk served as deputy president until 1996, when his party withdrew from the Cabinet. In making history, de Klerk acknowledged that Mandela's release was the culmination of what his predecessor, former President P.W. Botha, had begun by meeting secretly with Mandela shortly before leaving office. In the late 1980s, as protests inside and outside the country continued, the ruling party had begun making some reforms, getting rid of some apartheid laws.