Saudi Arabia hosts the G20 summit Saturday in a first for an Arab nation, with the virtual forum dominated by efforts to tackle the coronavirus pandemic and the worst global recession in decades.
The two-day meeting of the world's wealthiest nations comes as President Donald Trump refuses to concede a bitter election and campaigners criticise what they call the G20's inadequate response to the crippling economic crisis.
World leaders will huddle virtually as international efforts intensify for a large-scale roll out of coronavirus vaccines after a breakthrough in trials, and as calls grow for G20 nations to plug a $4.5 billion funding shortfall.
Amid a raging pandemic, the summit -- usually an opportunity for one-on-one engagements between world leaders -- is reduced to brief online sessions of what some observers call "digital diplomacy".
The pandemic dampened Saudi Arabia's hopes of using the event as a grand coming-out party on the world stage. Still, the kingdom hosted a gala musical event on the eve of the summit and planned an aerial display of its passenger and aerobatic planes over Riyadh on Saturday.
Without an opportunity to take the traditional "family photo", at the gala they projected a group portrait of G20 leaders onto the ruins of the historical town of Diriyah, close to the capital.
Saudi Arabia's King Salman will preside over the meeting, with sources close to the organisers saying climate change was among the issues topping the agenda.
German Chancellor Angela Merkel, Chinese President Xi Jinping and Russian leader Vladimir Putin are among leaders expected to make speeches, the sources said.
Trump will also participate, a US official said. Turkish President Recep Tayyip Erdogan will hold a briefing on Saturday, according to organisers.
"The G20 committed in March to do 'whatever it takes to overcome the pandemic and protect lives and livelihoods,'" British Prime Minister Boris Johnson said, referring to an earlier forum.
"As we meet this weekend, we must hold ourselves to account for that promise."
G20 nations have contributed more than $21 billion to combat the pandemic, which has infected 56 million people globally and left 1.3 million dead, and injected $11 trillion to "safeguard" the virus-battered world economy, organisers said.
The Paris-based Organisation for Economic Cooperation and Development projects global economic output will contract by 4.5 percent this year.
But G20 leaders face mounting pressure to help stave off possible credit defaults across developing nations.
Last week, the bloc's finance ministers declared a "common framework" for an extended debt restructuring plan for virus-ravaged countries, but campaigners say the measure is insufficient.
The ministers had extended a debt suspension initiative for developing countries until June next year.
UN Secretary-General Antonio Guterres urged G20 leaders to offer a "firm commitment" to extend the initiative until the end of 2021.
International Monetary Fund managing director Kristalina Georgieva has warned that the global economy faces a hard road back from the Covid-19 downturn even as vaccines are now in sight.
G20 nations must help plug a $4.5 billion funding gap in the so-called ACT-Accelerator -- a programme that promotes an equitable distribution of COVID-19 vaccines -- to rein in the pandemic, said a joint letter to the group from Norway's prime minister, South Africa's president, the heads of the European Union and the World Health Organization.
US Secretary of State Mike Pompeo, a staunch Trump defender, will be in Saudi Arabia on the second day of the summit.
It was unclear whether Trump, who continues to reject his election loss, will speak at the event. Many of his fellow G20 leaders have already congratulated his rival, President-elect Joe Biden.
Ahead of the summit, European Commission President Ursula von der Leyen said she hoped the US will adopt a more multilateralist stance under Biden.
"We also expect of course new momentum from the new US administration" on climate change, reversing Trump's withdrawal from the Paris climate accord, she added.
Saudi Arabia's human rights record has cast a shadow on the gathering, as campaigners and families of jailed activists launch vigorous drives to highlight the issue.
Key among them are the siblings of jailed activist Loujain al-Hathloul, on hunger strike for more than 20 days demanding regular family contact.
But some Western officials have indicated human rights will not be raised at the summit, saying they prefer to use bilateral forums to discuss the issue with the Saudi government.
"The G20 presidency has conferred an undeserved mark of international prestige on the (Saudi) government," said Michael Page, from Human Rights Watch.
"Instead of signalling its concern for Saudi Arabia's serious abuses, the G20 is bolstering the Saudi government's well-funded publicity efforts to portray the country as 'reforming' despite a significant increase in repression."
