President Jacob Zuma must repair the damage he has done to the fight against HIV/Aids, Democratic Alliance (DA) leader Helen Zille said on Saturday.

She was responding to Zuma's midday apology over his lovechild with Sonono Khoza.

" Zuma must now match words with deeds... The DA welcomes President Zuma's apology to the South African public. But words are not enough, he must now focus on repairing the damage he has done to the fight against HIV/Aids," she said.

"It is worth recalling that Jacob Zuma has apologised in exactly these terms before. He must show that his deeds match his words. Leadership is as leadership does."

She said that the South African public would not be so forgiving next time around.

The African National Congress and the Congress of South African Trade Unions (Cosatu) also welcomed Zuma's apology, describing it as honest.

"This is the President's own initiative, and it demonstrates his humility and integrity," Cosatu spokesperson Patrick Craven said.

"The majority of South Africans will reciprocate this by giving him the benefit of the doubt. It is good that the President realises that he erred and did not seek to take our people for granted. The apology was the right thing to do," he said.

The ANC, meanwhile, said it appreciated the President's apology regarding his personal relationships.

"In his response the President has shown integrity and honesty, thereby taking the country and its citizenry in his confidence," spokesperson Ishmael Mnisi said.

Zuma, who has three current wives and a fiancée, said that he regretted the pain this incident had caused his family and South Africa.

He admitted that his child with Sonono Khoza, daughter of soccer boss Irvin Khoza, was born out of wedlock.

Zuma, a polygamist, said that he had taken responsibility for his actions and had conducted the required "cultural imperatives" - the formal acknowledgement of paternity and responsibility, including the payment of inhlawulo to the family.

The baby girl, who was born in October, was reportedly the president's tweniteth child.

"I deeply regret the pain that I have caused to my family, the ANC, the (tripartite) alliance and South Africans in general," Zuma said.

"I also acknowledge and understand the reaction of many South Africans," he said.

The ANC again asked political parties and the public to give the families concerned privacy and "the opportunity to reflect on this matter." The Inkatha Freedom Party said it would comment on the matter shortly.