The current coronavirus outbreak is the biggest challenge for the world since World War Two, UN Secretary General António Guterres has warned.
He said it could bring a recession "that probably has no parallel in the recent past".
Mr Guterres was speaking at the launch of a UN report on the potential socioeconomic impact of the outbreak.
The number of confirmed cases around the world is now nearing 860,000, with more than 42,000 deaths.
The death toll in the US is now more than 4,000 - higher than the declared number of fatalities in China, where the outbreak began late last year.
More than 189,000 people in America have been infected, according to the data compiled by Johns Hopkins University.
About three out of four Americans are now, or about to be, under some form of lockdown, as more US states tighten measures to fight the coronavirus, which causes the Covid-19 disease.
Meanwhile, Spain, second only to Italy in the number of recorded fatalities, has seen 849 deaths in the last 24 hours - the highest number it has had in a single day.
In the UK, a total of 1,789 people have died - a rise of 381, officials say. Among the victims was a 13-year-old boy, King's College Hospital Trust in London said.