China's President Xi Jinping claps at the BRICS Summit in Johannesburg, South Africa, on Wednesday. Reuters

A deal to expand the BRICS group of leading developing countries appeared stuck in eleventh hour negotiations at a leaders summit on Wednesday, threatening to undermine the bloc's ambition to give the "Global South" more clout in world affairs.

Agreement to expand BRICS — currently Brazil, Russia, India, China and South Africa — could allow dozens of interested nations to seek admission as Beijing and Moscow push to forge it into a viable counterweight to the West.

The debate over enlargement has topped the agenda at the three-day summit taking place in Johannesburg. And while all BRICS members have publicly expressed support for growing the bloc, there were divisions among the leaders over how much and how quickly.

Summit host South Africa's foreign minister Naledi Pandort speaking on Wednesday said BRICS leaders had agreed on mechanisms for considering new members.

"We have agreed on the matter of expansion," she told a radio station run by her ministry.

BRICS group leaders walk after posing for a picture at the BRICS Summit in Johannesburg, South Africa. Reuters

"We have a document that we've adopted which sets out guidelines and principles, processes for considering countries that wish to become members of BRICS...That's very positive."

However, a BRICS member country official with direct knowledge of the discussions told Reuters that the leaders had not yet signed a finalised admission framework.

An agreement had been meant to be adopted following a plenary session earlier on Wednesday, but the source said it had been delayed after Indian Prime Minister Narendra Modi introduced new admission criteria.

Asked about the delay, an Indian official aware of the details of the talks told Reuters late on Wednesday that the discussion were continuing.

Sergei Lavrov (left) and Naledi Pandort pose for a photo prior at the 2023 BRICS Summit, in Johannesburg. AP

"Yesterday ... India pushed for consensus on criteria as well as the issue of (candidate) names. There was a broad understanding," he said.

Last-minute spoiler

BRICS countries have economies vastly different in scale and governments with often divergent foreign policy goals, a complicating factor for a bloc whose consensus decision-making model gives each member a de facto veto.

Bloc heavyweight China has long called for an expansion of BRICS as a means of fostering a multipolar world order to challenge Western dominance.

"The world ... has entered a new period of turbulence and transformation," China's President Xi Jinping said on Wednesday. "We, the BRICS countries, should always bear in mind our founding purpose of strengthening ourselves through unity."

Narendra Modi and Cyril Ramaphosa arrive at the 2023 BRICS Summit in Johannesburg, South Africa. Reuters

Russia's President Vladimir Putin, who is wanted under an international arrest warrant for alleged war crimes in Ukraine and is attending the summit remotely, is keen to show Western powers he still has friends.

Brazil and India, in contrast, have both been forging closer ties with the West.

Brazil's President Luiz Inacio Lula da Silva on Tuesday rejected the idea the bloc should seek to rival the US and Group of Seven wealthy economies.

The BRICS country official said that admission criteria India's Modi proposed included requiring members not be the target of international sanctions, ruling out potential candidates Iran and Venezuela.

Modi was also pushing for a minimum per capital GDP requirement.

"These are the things Modi brought in today," the official said. "So they are becoming a little bit of a spoiler."

Reuters