US Treasury Secretary Janet Yellen said she was "very concerned" that the highly transmissible Delta strain of the coronavirus could derail the global economy's recovery.
The strain, which fuelled a devastating outbreak in India, has put governments on watch around the world.
Delta has put millions of Australians under lockdown, while several European countries have seen cases spike as it takes hold among the unvaccinated, many of whom are young people.
Health officials in the US said on Wednesday that Delta had become the dominate strain there.
"We are very concerned about the Delta variant and other variants that could emerge and threaten recovery. We are a connected global economy - what happens in any part of the world affects all other countries," Yellen said at a meeting of G20 finance ministers in the Italian city of Venice on Sunday.
"We therefore recognize the importance of working together to speed the process of vaccination," she said.
Source: DPA
