Brazilian President Luiz Inácio Lula da Silva said on Tuesday the Brics group of emerging countries is not meant to challenge other international coalitions, such as the G7, or the United States, but to "organize" the so-called Global South.

"We do not want to be a counterpoint to the G7, G20 or the United States," Lula said in a live broadcast on social media as he attends the Brics summit in South Africa. "We just want to organize ourselves."

The leftist leader again defended a common trading currency for Brics countries, saying the move would not be aimed at "rejecting" the US dollar but instead facilitating trade between the emerging nations in their own currencies.

He said he supported other countries joining Brics - currently made up of Brazil, Russia, India, China and South Africa - but with certain conditions, "so it does not become a Tower of Babel."

"We want Brics to be a multilateral institution, not an exclusive club," Lula said, adding the he was particularly in favour of Argentina joining the group.

More than 40 countries have expressed interest in joining Brics, according to South African officials.