The president said the 94-year-old Nobel laureate is "responding better" and officials are "very happy" with his progress, the British newspaper The Guardian reported.
Speaking to parliament, Zuma added: "We appreciate the message of support from all over the world. It is an honor for us as South Africans to share Madiba with the international community."
Mandela, the country's first black president and winner of the Nobel Peace Prize, was taken to the hospital Saturday.
Mandela has been in hospitals several times in recent years. He hasn't appeared in public since South Africa hosted the World Cup in 2010.
Well-wishers gathered at churches and monuments to the former president to pray for his recovery, The New York Times reported Wednesday.