Group of 20 leaders adopted a declaration addressing the climate crisis and other global challenges over US objections, prompting the White House to accuse South Africa of weaponising its leadership of the group this year.
The declaration, which was drafted without input from the United States, "can't be renegotiated," South African President Cyril Ramaphosa's spokesperson told reporters, reflecting strains between South Africa and US President Donald Trump's administration, which boycotted the event.
"We had the entire year of working towards this adoption and the past week has been quite intense," spokesperson Vincent Magwenya said.
Hours later, the White House said Mr Ramaphosa was "refusing to facilitate a smooth transition of the G20 presidency" after initially saying he would pass the gavel to 'an empty chair.'"
"This, coupled with South Africa’s push to issue a G20 Leaders Declaration, despite consistent and robust US objections, underscores the fact that they have weaponised their G20 presidency to undermine the G20’s founding principles," said White House spokeswoman Anna Kelly.
Mr Trump looks forward to "restoring legitimacy" to the group next year, when the US holds the rotating presidency.
Mr Ramaphosa, host of this weekend's gathering of Group of 20 leaders in Johannesburg, had earlier said there was "overwhelming consensus" for a summit declaration.
But at the last minute Argentina, whose President Javier Milei is a close ally of Mr Trump, quit the negotiations right before the envoys were about to adopt the draft text, South African officials said.
"Argentina, although it cannot endorse the declaration, remains fully committed to the spirit of cooperation that has defined the G20 since its conception," its foreign minister Pablo Quirno said at the summit.
Mr Ramaphosa noted this, but went ahead with it anyway.
In explanation, Mr Quirno said Argentina was concerned about how the document referred to geopolitical issues.
"Specifically it addresses the longstanding Middle East conflict in a manner that fails to capture its full complexity," he said.
"The document mentions the conflict once, saying members agree to work for a just, comprehensive, and lasting peace in the Occupied Palestinian Territory," he added.
Declaration mentions climate change
Envoys from the G20 - which brings together the world's major economies - drew up a draft leaders' declaration on Friday without US involvement, four sources familiar with the matter said.
"It is a longstanding G20 tradition to issue only consensus deliverables, and it is shameful that the South African government is now trying to depart from this standard practice," a senior Trump administration official said.
The mention of climate change was a snub to Mr Trump, who doubts the scientific consensus that global warming is caused by human activities. US officials had indicated they would oppose any reference to it in the declaration.
In opening remarks to the summit, President Ramaphosa said: "We shouldn't allow anything to diminish the value, the stature and the impact of the first African G20 presidency."
Trump rejects South Africa’s G20 agenda
The summit came at a time of heightened tensions between world powers over Russia's war in Ukraine and fraught climate negotiations at the COP30 in Brazil.
"While the G20 diversity sometimes presents challenges, it also underscores the importance of finding common ground," Japan Cabinet Public Affairs Secretary Maki Kobayashi told Reuters.
Commenting on Argentina's absence from the final envoy meeting to agree on the text, Mr Magwenya said: "Argentina (had) been participating quite meaningfully in all the deliberations," then never showed up to endorse the declaration on Friday.
He added: "We have what we call sufficient consensus."
The US president had also rejected the host nation's agenda of promoting solidarity and helping developing nations adapt to weather disasters, transition to clean energy and cut their excessive debt costs.
"This G20 is not about the US," South African Foreign Minister Ronald Lamola told public broadcaster SABC.
"We are all equal members of the G20. What it means is that we need to take a decision. Those of us who are here have decided this is where the world must go," he added.
But in a sign of the many geopolitical fissures underlying the agreed text, EU Commissioner Ursula von der Leyen warned in a speech about "the weaponisation of dependencies" which she said "only creates losers".
This was an apparent veiled reference to China's export curbs on rare earths vital for the world's energy transition, as well as defence and digital technology.
The South African presidency yesterday reiterated its rejection of a US offer to send the US charge d'affaires for the G20 handover.
"The president will not hand over to a junior embassy official the presidency of the G20. It's a breach of protocol that is not going to be accommodated," Mr Magwenya said.
Mr Lamola later said that South Africa would assign a diplomat of the same rank as a charge d'affaires to hand over the G20 presidency at the foreign affairs department.