The Group of 20 finance leaders warned economic recovery is threatened by an upsurge of Covid-19 variants and poor access to vaccines in developing nations, as the world's virus cases hit 186.4 million with 4 million deaths Sunday, based on tracking by Johns Hopkins University.

First detected in India, the highly contagious Delta variant is sweeping the world as nations scramble to vaccinate their populations to contain new outbreaks and allow for economies and daily life to normalize.

"The recovery is characterized 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 and different paces of vaccination," Agence France-Presse quoted the G-20 as saying in a joint statement Saturday.

The G-20 meeting was held in Venice and was the ministers' first face-to-face gathering since the pandemic broke out.

The main focus of the meeting is the Delta variant, which is spreading rapidly, triggering outbreaks in Asia and Africa, and driving up the number of infections in Europe and the United States.

The finance chiefs reaffirmed their resolve to "use all available policy tools for as long as required" to address the adverse consequences of the worldwide health crisis, especially on the most vulnerable, like the elderly, women, children and informal and low-skilled workers.

The European Union said Saturday it has delivered a substantial amount of vaccines to cover 70% of the bloc's population.

Italy's Finance Minister Daniele Franco, in a news conference Saturday, said the G-20 "recognises the role of vaccination as a worldwide public good and reiterates its support for all collaborative efforts," The National reported.

Britain's Rishi Sunak, in an interview with Agence France-Presse, said the UK had shown "vaccines are effective at preventing hospitalisations and deaths, even with the Delta variant."

Meanwhile, differences in inoculation levels between the world's wealthy and poor remain vast. World Health Organization Director-General Tedros Adhanom Ghebreyesus has called the disparity a "moral outrage" that also affects the broader effort to curb the spread of the disease.