"I have considered many candidates for the national director of public prosecutions and, unless something unexpected happens, I will make the appointment before the end of August," Zuma was quoted as saying in papers submitted to the Constitutional Court on his behalf on Wednesday.
The Council for the Advancement of the South African Constitution (Casac) reportedly approached the court seeking an order that Zuma make the appointment within 30 days.
According to Beeld, the watchdog organisation claimed South Africans' safety, freedom and equality were at stake unless Zuma appointed an national director of public prosecutions to ensure the National Prosecuting Authority's (NPA) independence, stability and efficiency.
The NPA has been without a permanent chief since November 2011 after Menzi Simelane's appointment was declared invalid.
In the court papers, Zuma reportedly said the NPA was neither in a state of crisis, nor unstable.
Beeld reported that he claimed to have considered a number of candidates, but to have rejected them, for confidential reasons.
Zuma reportedly said the appointment process was almost complete, and he denied that any "improper motive or agenda" was behind the delay.
Institute for Accountability in Southern Africa director Paul Hoffman, reportedly told Beeld Casac deserved praise because it had forced Zuma to commit to a date.
Spy tapes
Zuma was criticised heavily for not appointing someone to the position, especially after corruption charges against him were dropped by the NPA even though reports suggested that prosecutors were overwhelmingly in favour of going ahead with charges against him.
The charges were dropped against Zuma before he was chosen as president, and the controversial spy tapes were dismissed by the NPA.
Last year, the parliamentary oversight committee on justice said it was concerned about the length of time it has taken to appoint a head to the NPA, saying that alleged criminals like Radovan Krejcir, Andrew Phillips and Glenn Agliotti escaped prosecution because there is no national director of public prosecutions.
But Deputy Justice Minister Andries Nel said he was not a concern as the NPA had other representatives in the structure, including four national deputy directors of prosecution, nine provincial directors and over 3 000 prosecutors.
The current acting national director of public prosecutions, Jiba, has her own controversies. She was suspended from a senior position in the NPA four years ago by its then-head, Mokotedi Mpshe, after facing internal charges of unprofessional conduct, dishonesty, fraud and bringing the NPA into disrepute.– Sapa, additional reporting by Staff Reporter