Iran, Argentina, Egypt, Ethiopia, Saudi Arabia and the United Arab Emirates will be joining BRICS from January 1 next year, South Africa's president has said.

The debate over expanding the BRICS bloc - made up of Brazil, Russia, India, China and South Africa - has topped the agenda at the summit in Johannesburg.

There have been divisions about whether expansion now is the best move.

The group wants to gain more influence in the world.