When it assumed the presidency of the G20 last year, South Africa hoped that as the first African country to host the gathering of world leaders, it could champion issues that mattered the most to developing nations.

For instance, it wanted the 20 heads of state from the world’s biggest economies to consider arguments that borrowing should be cheaper for developing countries, which pay two to four times more in interest on debts than more advanced economies.

Other themes of this weekend’s summit include securing climate change financing, increasing the participation of African countries in multilateral forums and ensuring that they get the best value out of their critical minerals.

But so far, discourse surrounding the meeting has been dominated by Donald Trump’s very public decision not to attend.

The US president said he would not go due to the widely discredited claim that South Africa’s white minority is the victim of large-scale killings and land grabs.

The relationship between the two countries has become increasingly fraught over the past year – the US expelled the South African ambassador to Washington, cut some of its aid funding and slapped South Africa with tariffs of 30% (the highest rate in sub-Saharan Africa).

And finally, after initially saying he would send Vice-President JD Vance to the G20 summit, Trump abruptly announced two weeks ago that no US representatives would attend.

The government in South Africa’s capital, Pretoria, has tried to maintain a defiant but diplomatic tone. It has firmly denied claims of a white genocide and insisted that the summit would proceed with or without the US.

In a sudden about face, and with less than 48 hours to go before the G20 conference, the US announced that it would be sending a small team of its in-country diplomats to the handover ceremony, but that it wouldn’t take part in any discussions.

As tension between the two nations shows no sign of letting up, there are concerns that South African diplomats may be frozen out of meetings when the US takes over the G20 presidency next year.

South Africa’s Finance Minister, Enoch Godongwana, told reporters earlier this week that there’s only one way they would not attend next year’s meetings.

“We are members of the G20, we’re not an invited country. So we don’t need an invitation from anybody,” he said.

“If the United States do not want us to participate, the only way they can do it is to decline us visas.”

So will South Africa manage to reach its aims without the presence of the world’s wealthiest nation? Professor Richard Calland, from the Cambridge Institute for Sustainability Leadership, thinks it can.

“I think that people who are serious-minded in their analysis will not attach much weight to [the US’ absence],” he says.

“Ironically, the absence of President Trump may create more space for real consensus, because people won’t be constantly looking over their shoulder at him and trying to anticipate or navigate his conduct and his positioning.”

Prof Calland adds that the absence of the US may enable middle powers to step up and push for the reforms they want by issuing a joint declaration.

Answering reporters’ questions at the summit’s venue in Johannesburg on Monday, South African Foreign Minister Ronald Lamola echoed this sentiment.

“[The United States] are absent, so in their absence, the countries that are present must make a decision.

“We are forging ahead to persuade the countries that are present that we must adopt a leaders’ declaration because the institution cannot be bogged down by someone who’s absent,” he said.

The leaders’ declaration is a culmination of work done throughout the year to build consensus on issues affecting the global economy, including trade barriers, technological advancements and climate change. It outlines what decisions the members have agreed to act on moving forward.

President Trump isn’t the only head of state who will not be attending. China’s Xi Jinping is sending his Premier Li Qiang, who has represented the president in a number of meetings this year.

Russian leader Vladimir Putin will also be absent due to the International Criminal Court’s warrant against him.

Mexico’s Claudia Sheinbaum is another leader who will not be attending.

And Argentinian President and Trump ally, Javier Milei, is skipping the summit in solidarity with Washington.

However, unlike the US, all of these countries are sending senior delegations to represent their countries’ interests.

Mr Lamola was keen to downplay the significance of these absences, saying sometimes heads of state are not able to attend major events, and it is “nothing abnormal” for them to send a replacement.

Other global powers have expressed their support of South Africa’s presidency of the G20, including France, the UK and the European Union, which signed a deal with South Africa on Thursday agreeing to boost the extraction and, more importantly, the domestic processing, of critical minerals.

African countries have long argued that processing minerals in their countries before exporting them would boost their economies by providing much-needed development, jobs and income.

These are the types of initiatives that Pretoria has spent the year lobbying for across various working groups and ministerial meetings.

South Africa is the last G20 country to take over the presidency in this current cycle. It’s also the last country in the global south to host the gathering. Indonesia, India and Brazil have led the summit over the past three years.

As such, the South African government says it wants to use its presidency to bridge the developmental divide between the global north and south. It wants to push for equity, sustainability and shared prosperity.

Although building consensus through multilateral institutions like the G20 is becoming increasingly fraught in a divided world, Prof Calland argues that it is needed more than ever.

“Human life on Earth is facing an existential set of challenges, whether it’s climate change, demographic shifts, technological revolution and so on.

“All of these are hugely difficult pressure points for human society. And you can’t deal with them unless there is international collaboration and cooperation,” he says.

President Trump and his supporters argue that multilateral organisations do little to change real people’s lives, preferring instead bilateral deals done directly between two countries.

But South Africa and other developing countries argue that issues like reducing the cost of borrowing for poorer countries require the input of international institutions like the IMF and cannot be done through one-on-one deals.

In many ways, South Africa’s presidency of the G20 is part of a wider debate around multilateralism and its effectiveness.

If South Africa is able to convince other G20 members to issue a joint declaration on Sunday, it might have succeeded in proving that consensus can be reached without the participation of the world’s most powerful country.