The pandemic, which has claimed more than 1.37 million lives worldwide, has offered the G-20 an opportunity to prove how such bodies can facilitate global cooperation in crises - but has also underscored their shortcomings.
"It is unfortunate that we are unable to host you in person in Riyadh, due to the exceptional circumstances that we are all facing this year", King Salman, the summit's hosts, told world leaders in opening remarks via videoconference.
The statement did not commit any specific amount of funding to the Access to Covid-19 Tools (ACT) Accelerator and its vaccine facility, COVAX, which aims to distribute vaccine doses to developing countries.
G20 members are: Saudi Arabia, the United States, Turkey, Canada, Mexico, Brazil, Argentina, France, the United Kingdom, Germany, Italy, South Africa, Russia, China, Japan, South Korea, India, Indonesia, Australia, and the EU.
It was the first time for G20 leaders to hold a summit virtually ever since the mechanism, which used to only gather finance ministers and central bankers, was elevated to be the world's premier platform for global economic cooperation in 2008.
The virus shows no signs of abating as major cities in the USA and Europe bring back lockdowns and curfews.
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 International Labor Organization says an equivalent of 225 million full-time jobs were lost in G-20 countries alone in the third quarter of 2020. The group's member-countries represent around 85% of the world's economic output and three-quarters of worldwide trade.
In a comment echoed by other world leaders, French President Emmanuel Macron said Saturday that the coronavirus crisis was "a test for the G20", stressing there "will be no effective response to the pandemic unless it is a global response".
"Our fates are in each other's hands", he said. The economic crisis arising as a effect of the virus has dominated the agenda at the two-day summit.
"From the very beginning, we have emphasized that we should take care of people's health and of the economy at the same time".
President Trump, meanwhile, is among other G-20 leaders expected to participate in the closed-door virtual sessions that are taking place Saturday and Sunday.
"We must first put the disease under control at home and, on that basis, strengthen exchanges and cooperation to help countries in need", he said.
G-20 heads of state last gathered virtually for an emergency meeting in March as the coronavirus was fast-spreading around the world. They also promised to work together to increase funding for vaccine research.
"We will spare no effort to ensure their affordable and equitable access for all people, consistent with members' commitments to incentivise innovation".
Ahead of the summit, U.N. Secretary-General António Guterres urged leaders of the countries to view widespread distribution as a matter of public health for the entire world as well as a humanitarian concern.
"The communique certainly identifies the challenges, but has made no substantive, significant progress in addressing COVID, climate change, the debt situation in many developing countries", Bernes said.
The summit also included talk of bolstering the world's pandemic response programs to better prepare for any future health scare.
World leaders have huddled virtually as global 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.
U.S. President-elect Joe Biden has pledged to rejoin the Paris agreement, and while Trump has so far refused to accept his election defeat, courts in the U.S. continue to rule against his efforts to challenge the results, suggesting he will indeed be out of office in January.