The 83-year-old Nobel Peace Laureate was admitted to a Cape Town hospital earlier this week with a “persistent infection”.
His daughter has confirmed his hospitalisation if not linked to the prostate cancer he has been living with for more than a decade.
The Desmond and Leah Tutu foundation did not given any details about the Arch’s illness, except to say his treatment is unrelated to cancer.
Zuma has asked South Africans to keep Tutu in their thought and prayers. Earlier Anglican Archbishop Thabo Makgoba also offered words of support.
