In February 1990, South Africa's President F. W. de Klerk lifted the ban on political parties and promised to release political prisoners, including African National Congress (ANC) leader Nelson Mandela, Since then, representatives of the government and of the country's black majority have been engaged in prolonged negotiations over the transition from apartheid, the system of strict racial segregation which gave nearly all economic and political power to the 15 percent of the population legally classified "white."