Updated

The new leader of South Africa's ruling party and the country's likely next president is making his first speech as he tries to reunite the African National Congress at its weakest point since taking power at the end of apartheid.

Cyril Ramaphosa, once Nelson Mandela's preferred successor, is proclaiming a "victory over the doomsayers" after some observers said the party could split amid growing frustration over scandal-prone President Jacob Zuma.

Ramaphosa says the thousands of ruling party delegates have seen Africa's oldest liberation movement "at its worst ... divided against itself."

But the deputy president, who now faces the challenge of reviving the economy and the country's trust in the ANC ahead of 2019 elections, says that "we are alive, we are leading and we are here to stay."