The IMF on Wednesday laid out the unprecedented economic devastation caused by the coronavirus pandemic, as the WHO said it expects the number of global infections to soon hit 10 million and cases surge in the Americas.
The International Monetary Fund said that this "crisis like no other" would send the global GDP plunging by 4.9 percent this year and wipe out an astonishing $12 trillion over two years.
As many countries emerge from lockdowns hoping to resurrect their economies, the IMF warned that a potential second wave of infections could mean its already grim World Economic Outlook update underestimates the damage.
It said that many countries will face a recession more than double that which they suffered during the global financial crisis in 2008-2009.
The IMF forecast that China, where the virus emerged late last year, would be the only economy that grows this year, by just one percent.
The United States is forecast to shrink by eight percent, Germany slightly less, while France, Italy, Spain and Britain would all suffer double-digit contractions.
The report said the crisis would particularly affect low-income countries and households, as well as threatening progress made on reducing extreme poverty.
- 'Sober reminder' -
World Health Organization chief Tedros Adhanom Ghebreyesus said the global number of cases would reach 10 million within the next week after four million cases were recorded just in the last month.
The global figure currently stands at over 9.3 million.
"This is a sober reminder that even as we continue research into vaccines and therapeutics, we have an urgent responsibility to do everything we can with the tools we have now to suppress transmission and save lives,' he said.
WHO emergencies director Michael Ryan warned that the pandemic had not yet reached its peak in the Americas.
He said it was "particularly intense in Central and South America" where many countries saw "between a 25 and 50 percent rise in cases over the last week".
Without isolating and quarantining contacts, "the spectre of further lockdowns cannot be excluded," he added.
Globally, the number of COVID-19 deaths surged past 477,000 on Wednesday after doubling in less than two months, according to an AFP tally.
China said a new outbreak that has infected 256 people in Beijing since early June is "under control", but fears remain over the risk of community transmission.
Experts warned that small, recurrent outbreaks of the virus were likely in future.
Hard-hit Europe is reopening from lockdown after seeing the numbers of new cases and fatalities fall.
But Slovenia reinstated the mandatory use of masks in indoor spaces on Wednesday after recording a rise in cases.
It came a day after Germany reimposed restrictions on more than 600,000 people following a cluster of infections at a slaughterhouse.
And in Britain, medical experts warned of the "real risk" of a second wave and called for a swift review into the government's handling of the outbreak, a day after the biggest lifting of measures yet in England.
Experts have also warned that an early summer heatwave across the continent could lead to a surge in infections as people hit beaches and parks while ignoring social distancing measures.
No masks were worn by participants -- and few by spectators -- at a huge parade in Moscow during World War II commemorations on Wednesday.
The pandemic also continues to cause havoc in global sports, with New York cancelling its famed marathon which had been planned for November 1.
World men's tennis number one Novak Djokovic tested positive after an exhibition tournament in the Balkans, drawing widespread condemnation for organising the event.
- 'Not out of the woods' -
The United States has recorded more deaths than any other nation, with more than 121,000 from nearly 2.5 million cases.
White House advisor Anthony Fauci warned the next two weeks would be "critical to our ability to address... surgings" in Florida, Texas and other states.
President Donald Trump, whose handling of the crisis has been widely criticised, meanwhile doubled down on comments that he had wanted to slow testing because so many official infections made the US look bad.
"I don't kid," Trump said, after a White House official described his initial comments as just a joke.
Latin America has been one of the world's worst hotspots for weeks, and
The number of deaths in Latin America and the Caribbean surpassed 100,000 on Wednesday, with Brazil the hardest-hit country.
A federal judge ordered Brazil's President Jair Bolsonaro, who has famously compared coronavirus to a "little flu," to wear a mask in public, after the far-right leader repeatedly flouted containment measures.
The IMF said the coronavirus pandemic would particularly affect low-income countries and households
A heatwave has hit much of Europe, with experts warning it could lead to a surge in infections
No masks were worn by participants -- and few by spectators -- at a huge parade in Moscow during World War II commemorations
Novak Djokovic has apologised after organising a widely criticised tournament then testing positive for coronavirus
IMF growth forecasts for 2019-2021 for world regions and selected countries