"As we mark the 50th anniversary of the OAU [Organisation for African Unity] we must intensify our efforts and our calls for the reform of the governing global order," he said in a statement.
Zuma explained that on 25 May 1963 leaders of 32 African independent states signed a charter establishing the OAU, which was the precursor of the African Union (AU).
He said the OAU provided a sense of purpose for the African people to restore their freedom, dignity and to strive for a better life for all Africans.
"While we rightfully celebrate the 50th anniversary, we are cognisant of the challenges we face," Zuma said.
"The road ahead to attain peace, stability and prosperity on the African continent for all her peoples is still arduous."
Challenges not insurmountable
He called on all leaders of the continent to sharpen their resolve and through the AU, raise their collective voices and confront current problems.
"As South Africa on this day we must also dedicate ourselves to unity, kinship and tolerance. We must work hard to eradicate from our society all forms of xenophobia, racism and related intolerances."
Zuma said Africa’s challenges were not insurmountable and the AU could build on the legacy left by the OAU.
"We must continue to work together to intensify Africa’s development through the New Partnership for Africa's Development (Nepad). The continent must map its journey through voluntary self-assessment through the African Peer Review Mechanism (APRM)."
Zuma said South Africa wished to encourage all member states, organs of the AU and the various regional economic communities to mark the milestone and to continue to work together for the realisation of a prosperous, peaceful and developed Africa.
"It is further hoped that as we rededicate ourselves to the task of the African Renaissance, we will spare no efforts to contribute resources to make our Union self-reliant and independent," he said.
"A free and self-sustaining Africa will be a pipe dream if we remain beholden to external sources."