Answer:
they were both President of South Africa. Mandela was after deKlerk. After Mandela ended up President he named de Klerk as his first deput.
It contends for the collaboration between government officials of all races that Mandela would satisfy in his exchanges with de Klerk to end politically-sanctioned racial segregation
In 1990, de Klerk offered requests to end South Africa's atomic weapons program; the procedure of atomic demilitarization was basically finished in 1991. ... In 1993, de Klerk and Mandela were together granted the Nobel Peace Prize for their work in consummation politically-sanctioned racial segregation.