As healthcare systems brace for damage inflicted by the quick-spreading Delta variant, G20 finance ministers warned Saturday that it could also slow global economic recovery.
"The recovery is characterised by great divergences across and within countries," and "remains exposed to downside risks, in particular, the spread of new variants of the Covid-19 virus", they said in a final statement.
The ministers also warned of the dangers of the "different paces of vaccination" around the world.
The main concern is the Delta variant, which first appeared in India and is spreading rapidly, causing outbreaks in Asia and Africa, and driving up case numbers in Europe and the United States.
"We have very good economic forecasts for all the G20 countries," French Economy Minister Bruno Le Maire said.
But he warned: "The only thing that could threaten a solid and rapid rebound of the economy is the variant, and a new wave of the pandemic.
"We must improve vaccination, everywhere in the world."
Britain's Rishi Sunak was more defiant, telling AFP in an interview that the UK had showed "vaccines are effective at preventing hospitalisations and deaths, even with the Delta variant."
"I think that gives us the confidence to move forward and slowly and safely reopen our economies and countries," he said.
'Support still needed'
Many countries, however, from Spain to Thailand, have moved to re-introduce anti-Covid restrictions.
All eyes in France will be on President Emmanuel Macron's speech Monday, when he will set out next steps as case numbers rise, while Argentina has extended its own measures until early August.
Rising concern over the Delta variant comes on the heels of the easing of restrictions in many countries, which has breathed much-needed fresh air into many of the major economies.
The G20 has called for vaccination campaigns worldwide to be accelerated, pledging to do more to help developing countries give their citizens jabs.
While 70 percent of the population is vaccinated in some developed countries, the figure is less than 1.0 percent for low-income countries, according to UN secretary general Antonio Guterres.
Equity markets were also spooked this week, as a report from the latest US central bank meeting showed a debate on tightening monetary support is underway, despite the ongoing health crisis.
Added to this are signs that the recovery in China is running out of steam.
Still, forecasts from major institutions are optimistic.
The European Commission this week raised its Europe growth expectations for 2021, saying it now forecasts a rise of 4.8 percent, compared to 4.3 percent previously.
Brussels is counting on the continued lifting of restrictions to boost growth, and vaccine programmes to limit the impact another coronavirus wave might have on the economy.
The International Monetary Fund was similarly upbeat, saying it expects the "fastest" growth in the US in 25 years.
The G20 finance ministers sounded a more cautious note however on Saturday, pledging to "continue to sustain the recovery, avoiding any premature withdrawal of support measures".