The summit takes place on Sunday.
"The Summit will mark the entry into force of the Agreement on the Establishment of the African Continental Free Trade Area (AfCFTA) and will formally launch the operational phase of the African Internal Market," said the spokesperson to the president Khusela Diko.
"The Summit will also decide on the location and structure of the AfCFTA Secretariat."
Diko said that at the Open Session of the Extraordinary Summit, President Ramaphosa would, alongside President Paul Kagame of Rwanda, participate in the launch of the Tariff Concession Portal.
"The password controlled tariff concession portal was created to allow countries ready to extend tariff preferences and or give concessions to do so in a secured manner. To this end, the aforementioned products will attract minimal or no tariff thus making them more competitive."
Diko said since its adoption, the AfCFTA had been signed by 52 countries, with 24 ratifications, thus ensuring its entry into force after it surpassed the threshold of 22 ratifications by AU Member States.
"South Africa deposited its Instrument of Ratification of the Agreement Establishing the AfCFTA on 10 February 2019," she said.
"The AfCFTA aims to make doing business on the continent easier and encourages African countries to trade among each other while addressing issues that stifle intra-African trade such as high transport costs, cumbersome customs, among others."