Saudi Arabia, which assumed the G20 presidency this year, is the host of the virtual summit that is bringing together leaders from the world's richest and most developed economies, such as the US, China, India, Turkey, France, the United Kingdom and Brazil, among others.
The communique also commits rich countries to holding off on collecting debt payments from impoverished nations, many of which are struggling to keep their heads above water during the pandemic.
"I am confident that the Riyadh summit will deliver significant and decisive results and will lead to adopting economic and social policies that will restore hope and reassurance to the people of the world, " King Salman said.
Russian President Vladimir Putin offered to provide Russia's Sputnik V coronavirus vaccine to other countries and said Moscow was also preparing a second and third vaccine.
India is scheduled to host the G20 summit in 2022.
G20 leaders, including US President Donald Trump who is refusing to concede a bitter election, popped up in multiple windows across a flickering screen, in a high-stakes webinar held amid the raging pandemic.
"We should speed up action and support the World Health Organization in mobilizing and consolidating resources and distributing vaccines fairly and efficiently", Xi said.
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.
Japan and New Zealand press for open markets to boost recovery
The Trump administration has been criticized for a lower level of engagement in Asia. Last year's summit in Chile was canceled due to violent protests.
"Going forward, we must also help those countries not covered by the Framework to address debt vulnerabilities so that their economies can become more resilient", IMF Managing Director Kristalina Georgieva said in a statement after addressing the G20 leaders.
Her words were echoed by French President Emmanuel Macron, who also adressed leaders.
But the group's leaders face mounting pressure to help stave off possible credit defaults across developing nations.
Saudi Arabia's King Salman said 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 ministers had extended a debt suspension initiative for developing countries until June next year but UN Secretary-General Antonio Guterres has pushed for a commitment to push it until the end of 2021. "China actively supports and participates in global cooperation on COVID-19 vaccines", he said.
While the global economy is recovering from the depths of the Covid-19 crisis, momentum is slowing in countries with resurging infection rates, the recovery is uneven and the pandemic is likely to leave deep scars, the International Monetary Fund said in a report for the G20 summit. President-elect Joe Biden has not said whether he will join it.
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 Riyadh. Human Rights Watch said the summit was "a mark of global prestige for the government of Crown Prince Mohammed bin Salman but it helps the Saudi government deflect from its image as a pervasive human rights violator".
The communique offered no details on how the effort will be funded.