G20 leaders said Sunday they will "spare no effort" to ensure fair distribution of coronavirus vaccines, but the united front was punctured by Germany's Angela Merkel who said progress was too slow.
At a virtual summit hosted by Saudi Arabia, the world's richest nations pledged resources to shore up the pandemic response, and to support poor countries whose economies have been ravaged by the crisis, but offered little detail.
The German Chancellor said she was concerned that no major vaccine agreements had yet been struck for poorer nations, even as rich countries have already bought up huge numbers of doses from pharmaceutical firms.
"We will now speak with (global vaccine alliance group) GAVI about when these negotiations will begin because I am somewhat worried that nothing has been done on that yet," Merkel told reporters in Berlin.
Saudi Arabia's King Salman said at the end of a weekend of digital diplomacy that the "spirit of cooperation" was needed now "more than ever to face the impact of the pandemic and create a prosperous future for the people of the whole world".
The group of 20 leading economies struck a positive tone in their closing communique.
"We have mobilised resources to address the immediate financing needs in global health to support the research, development, manufacturing and distribution of safe and effective Covid-19 diagnostics, therapeutics and vaccines," they said.
"We will spare no effort to ensure their affordable and equitable access for all people."
But as richer nations plan their vaccination programmes, with the US expecting to launch in early December, experts warn that developing countries face hurdles that could deny billions the first proven protection against the virus.
Calls are mounting for the G20 to help plug a $4.5-billion funding gap in the so-called ACT-Accelerator, a mechanism led by the World Health Organization that aims to ensure access to tests, treatments and vaccines for all.
"I am glad that G20 leaders agreed to make Covid-19 vaccines available and affordable for all. But more funding is needed," said European Commission President Ursula von der Leyen, adding that she had called on leaders to commit to fund the project by the end of this year.
The unusual format of the summit, in place of a real-life meeting that coronavirus restrictions made impossible, has produced some awkward interactions, and deprived Saudi Arabia of an opportunity to showcase itself on the international stage.
US President Donald Trump made a brief appearance at the opening session, lauding his administration's achievements on coronavirus before logging off and going golfing, while other leaders braved technical quirks and the lack of opportunity for spontaneous conversations.
The mercurial president made another splash on Sunday, defending his decision to pull out of the Paris climate accord, calling it "unfair and one-sided" and designed to kill the "American economy".
In the communique though, the group adopted a consensus position on climate change, reiterating support for tackling "pressing" environmental challenges.
Differences within the G20 were made highly public at last year's summit in the Japanese city of Osaka, when the United States demanded the insertion of a separate paragraph on issues such as environmental protection.
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 shore up the battered world economy, summit organisers said.
In the communique, leaders said that in the face of an "uneven, highly uncertain" recovery they were "determined to continue to use all available policy tools as long as required to safeguard people's lives, jobs and incomes, support the global economic recovery, and enhance the resilience of the financial system".
But the group faces mounting pressure to help stave off possible credit defaults among poorer nations, as their debt soars amid the economic catastrophe stoked by the virus.
The G20 has extended a debt service suspension initiative (DSSI) for developing countries until June, but the United Nations has led calls for it to be prolonged until the end of 2021.
The communique did not offer any guarantee.
Instead, G20 finance ministers will examine the recommendation when the IMF and World Bank meet next spring "if the economic and financial situation requires" an extension by another six months, they said.
With the world in disarray after months of border closures and lockdowns, the group also struck a unified tone on trade, saying that supporting a multilateral system "is now as important as ever".
Saudi Arabia's human rights record has cast a shadow on the gathering, as campaigners and families of jailed activists launched vigorous drives to highlight the issue.
But the issue barely surfaced over the weekend, with Western officials indicating they prefer to use bilateral forums to discuss the issue with Riyadh.