African leaders have opened talks in Johannesburg on forming a 26-nation free trade bloc that would be the biggest on the continent.
The proposed Grand Free Trade Area would join three existing trade blocs - the East African Community, the Southern African Development Community and the Common Market for Eastern and Southern Africa.
The three blocs have different rules, and some countries belong to more than one group, complicating efforts to increase and streamline African trade.
Supporters of the expanded free trade zone say it would reduce tariffs for large companies in the region, and would give small nations access to a regional market.
Swaziland's King Mswati, who heads one of Africa's smallest economies, endorsed the proposal Sunday, although he said implementation should proceed slowly.
Stronger backing came from South African President Jacob Zuma, who said, "There is no single country that can prosper on its own."
Analysts say the deal still faces possible stumbling blocks. Several of the countries involved are mired in political turmoil, most notably Libya, Madagascar, Sudan and Zimbabwe.