Embattled South African President Jacob Zuma and his deputy Cyril Ramaphosa are both set to feature at public events in Cape Town at the weekend, this as South Africa waits with bated breath on the future of their head of State who is widely expected to either step down or be forced out of office in coming days.

On a momentous day in national politics Wednesday, Parliament's presiding officers took the unprecedented step of postponing the state-of-the-nation address which had been scheduled for Thursday evening, while the ruling African National Congress (ANC) unexpectedly cancelled a crucial meeting that was supposed to provide clarity on Zuma's future.

Zuma will on Saturday officiate at the annual Ubuntu Awards ceremony at the Cape Town International Convention Centre, the Presidency confirmed. On Sunday, Ramaphosa, who succeeded Zuma as ANC president at the party's elective conference in December, is slated to be the main speaker at the Nelson Mandela Centenary Launch in Cape Town.

The Presidency said Zuma will be present at the Ubuntu awards which were first launched by the Department of International Relations and Cooperation in 2015, and "celebrate South African citizens who play an active role in projecting a positive image of South Africa internationally".

"Through excellence in their chosen fields, the proud South Africans are recognised for serving as global ambassadors of the nation. These are South African citizens, who, through their Integrity, Passion, Patriotism and Humility have raised the South African flag high on an international stage," the Presidency said.

The 2018 Ubuntu Awards will be held under the theme "Honouring Madiba; a global champion of human rights, peace and reconciliation" in honour of former president Mandela who would have turned 100 this year.

The ANC will launch the Nelson Mandela Centenary programme at the Grand Parade in the Cape Town CBD on Sunday, which also marks 28 years since Mandela was released from Victor Verster prison after spending 27 years in prison.

In a statement, the Western Cape ANC said: "The date for the Centenary Launch, 11 February, is very symbolic as it is the same day, 28 years ago, that Nelson Mandela was released from Victor Verster prison after spending almost a quarter of his life in prison. The Grand Parade is also etched in the country's memories as the place where the masses of our people gathered in their thousands to listen to Madiba speak to them for the first time in almost 30 years.

"This great symbolism gives the Launch of Madiba's centenary this Sunday its own special peace of history and great sense of occasion.

"The ANC invites all residents of the Western Cape to gather at the Grand Parade to listen to the ANC President, Comrade Cyril Ramaphosa, revisit that grand part of history to which he was also at the center, having been at the right hand of Madiba throughout that special day."

The news of the engagements of Zuma and Ramphosa come after the ANC late Tuesday said it had postponed Wednesday's meeting of its powerful national executive committee (NEC), which was expected to force Zuma to resign. The NEC meeting will now be held on 17 and 18 February.

The party said the NEC meeting was cancelled after "constructive discussion" between Zuma and Ramaphosa in Cape Town on Tuesday.

There have been rising calls for Zuma to step down and to not deliver the State of the Nation Address, both from within his own party and the opposition, who have in recent years disrupted the State of the Nation Address in protest at Zuma's presence amid myriad scandals of corruption and State capture.

Standing on the steps outside the National Assembly on Tuesday, Speaker Baleka Mbete said: "We have been dismayed in the past four years at the disruption, anarchy and chaos that have been characteristic of this annual Joint Sitting which, in some way, marks the opening of Parliament.

"We have, regrettably, come to the conclusion that there is little likelihood of an uneventful Joint Sitting of Parliament this coming Thursday."

If Zuma fails to resign the beleaguered former leader of the ANC faces a no-confidence motion in Parliament scheduled for 22 February, while there is also the possibility of impeachment proceedings being instituted. Zuma is also central to a state capture commission of inquiry, while decade-old corruption charges could soon be reinstated.