The world faces the most challenging crisis since the Second World War, UN secretary-general Antonio Guterres has said.
He warned the world was confronting a pandemic threatening people in every country, one that will bring a recession "that probably has no parallel in the recent past".
There is also a risk that the combination of the disease and its economic impact will contribute to "enhanced instability, enhanced unrest, and enhanced conflict", the UN chief said at the launch of a report on the socioeconomic impacts of Covid-19.
Mr Guterres called for a much stronger and more effective global response to the pandemic and to the social and economic devastation that Covid-19 is causing.
He stressed that this will only be possible "if everybody comes together and if we forget political games and understand that it is humankind that is at stake".
"We are facing a global health crisis unlike any in the 75-year history of the UN, one that is killing people, spreading human suffering, and upending people's lives," the report said.
"But this is much more than a health crisis.
"It is a human crisis.
"The coronavirus disease is attacking societies at their core."
The secretary-general told reporters: "The magnitude of the response must match the scale of the crisis - large-scale, co-ordinated and comprehensive, with country and international responses being guided by the World Health Organisation."
He stressed that "we are still very far from where we need to be to effectively fight Covid-19 worldwide and to be able to tackle the negative impacts on the global economy and the global societies". First, he said, many countries are not respecting WHO guidelines, with each tending to go its own way in dealing with the coronavirus pandemic.
"Let us remember we are only as strong as the weakest health system in our interconnected world," he said.
"It is essential developed countries assist those less developed to bolster their health systems and response capacity to stop transmission."
Secondly, he said, while £4 trillion has been mobilised, most was by the developed world to support their own economies.
"We are far from having a global package to help the developing world create the conditions both to suppress the disease and to address the dramatic consequences in their populations, in the people that lost their jobs, the small companies that are operating and risk disappearing, those that live with the informal economy that now have no chance to survive," he said.