President Zuma, speaking at the start of a major policy meeting of his ruling African National Congress, said the challenges of poverty, unemployment and inequality posed long-term risks for Africa's richest country 18 years after the end of apartheid.
He said: "The structure of the apartheid-era economy has remained largely intact. The ownership of the economy is still primarily in the hands of white males as it has always been."
The ANC has drafted a raft of policy documents that call on mining firms to pay more to the state to help finance welfare spending. The proposals also advocate relying on state-owned enterprises to be engines of job creation and growth.
Mr Zuma added."The time has come to do something more drastic towards economic transformation and freedom."
He also called for a new programme for land reform, saying the current "willing buyer-willing seller" policy had been too slow in returning white-owned farmland to blacks dispossessed by the apartheid state. But he did not spell out what alternative land ownership transfer should be adopted.