U.N. Secretary-General Antonio Guterres called Monday for massive and speedy COVID-19 vaccination campaigns in both developed and developing countries, urging rich nations to make their excess doses available to poorer ones.

"If we believe it is possible to vaccinate the global north and forget about the global south. If you let the virus spread like wildfire in the global south, it will mutate," Guterres warned in a virtual presentation at the World Economic Forum's Davos Agenda.

He cautioned that if the virus mutates, it could become resistant to the newly developed vaccines.

FILE - U.N. Secretary-General Antonio Guterres addresses the media in Berlin, Germany, Dec. 17, 2020. (Michael Sohn/Pool via Reuters)

"That risk is there. See what happens with the flu? Every year, we have to have a new vaccine on the flu because in between, the virus has mutated," he said. "Do we want the COVID to have that same situation?"

Guterres said vaccine production needs to be significantly scaled up.

"Licenses should be made available to the huge production capacity that exists, namely in several developing countries - countries like India, like Brazil - have huge capacity of production of generics and will have a huge capacity of production of vaccines if licenses are made available to them," he said. "And this will create, of course, the capacity to provide vaccines in large quantities also to developed countries and to the poorest areas of this world."

The secretary-general's remarks come as the global death toll from COVID-19 has surpassed 2 million and confirmed cases approach 100 million, according to Johns Hopkins University data. The vaccine rollout has been slow and clumsy in some of the richest nations, while virtually non-existent in some of the poorest.

FILE - Tedros Adhanom Ghebreyesus, WHO director general, speaks in Geneva, Jan. 21, 2021. (C. Black/WHO/Handout via Reuters)

One week ago, World Health Organization Director-General Tedros Adhanom Ghebreyesus said that 39 million doses of COVID-19 vaccine had been administered in at least 49 wealthier countries, but only 25 doses in one poorer country (Guinea).

The virus has also claimed millions of livelihoods and devastated national economies.

A U.N. report released Monday said the world economy shrank by 4.3% last year, and 131 million more people were pushed into poverty because of the pandemic.

Guterres appealed to leaders at all levels to use the pandemic to build back in a way that addresses social and economic inequalities and is kinder to the planet.

"We are doomed if we are not able to reconcile with nature," he warned.

He said the trillions of dollars needed for the global COVID-19 recovery are borrowed from future generations, who will also have to bear the most severe impacts of global warming.

Guterres called for half the total share of climate finance provided by all wealthy countries and international financial institutions to be earmarked for climate adaptation and resilience in developing countries.

"We have reached a moment of truth," he declared. "In 2021, we must address these fragilities and put the world on track. It is time to change course and take the sustainable path."