Announcing his resignation in a televised address on Wednesday night, Zuma stated, “The ANC should never be divided in my name. I have therefor come to the decision to resign as president of the republic, with immediate effect.”
An AP report said Zuma's resignation came after the ruling African National Congress party instructed him to leave office by the end of Wednesday or face the motion of no confidence in parliament.
His departure ended a leadership crisis in one of Africa's biggest economies and set the stage for ruling party lawmakers to elect acting president Cyril Ramaphosa, previously deputy president, as Zuma's successor.
"I have therefore come to the decision to resign as president of the republic with immediate effect," said Zuma, who added that he took the decision even though he disagreed with the ruling party's demand that he quit. Zuma, 75, had said he was willing to resign but wanted to stay in office for several more months.
"Of course, I must accept that if my party and my compatriots wish that I be removed from office, they must exercise that right and do so in the manner prescribed by the constitution," Zuma said.
The former president was defiant in a television interview earlier Wednesday, saying he had done nothing wrong.
"I'm being victimized here," Zuma told state broadcaster SABC. He complained that Ramaphosa and other ANC leaders had not given him clear reasons about why he should go.
The ANC, which has led South Africa since the end of white minority rule in 1994, had wanted Zuma to end his second five-year term early so that it could build up support ahead of 2019 elections.
"We can no longer keep South Africa waiting," said Paul Mashatile, the ANC's treasurer general.
Ramaphosa, elected as the ANC's new leader in December, has said the government will do more to fight the corruption that has damaged the ANC.
As the Gupta-linked investigation proceeds, Zuma also could face corruption charges tied to an arms deal two decades ago. South Africa's chief prosecutor is expected to make a decision on whether to prosecute Zuma on the old charges, which were reinstated last year after being thrown out in 2009.
"I need to be furnished on what I've done," Zuma said in the interview.
- Countries: Africa