The Secretary-General of the United Nations has warned that a global recession "is a near certainty" and current national responses to the coronavirus pandemic "will not address the global scale and complexity of the crisis".
"This is a moment that demands coordinated, decisive, and innovative policy action from the world's leading economies," Antonio Guterres told reporters via video conference.
"We are in an unprecedented situation and the normal rules no longer apply."
"A global recession - perhaps of record dimensions - is a near certainty," he said.
Mr Guterres' comments come on a day when the death toll from the coronavirus rose to over 9,000.
As of shortly after 5pm today, the total number of confirmed infections worldwide was 231,203.
Of these, 43% were on the European continent, with 92,700 of them in European Union alone.
It means the EU now has 11,700 more confirmed coronavirus cases that China. Globally, 86,261 people have already recovered from the disease, but there have been 9,390 deaths.
That leaves 135,552 people currently infected with 5% of them, or 6,938 people, described as serious or critical.
Overall, 65% of all cases have now occurred outside of China.
The number of confirmed cases has risen by 191, bringing the total to 557, according to the Department of Health.
"Our world faces a common enemy. We are at war with a virus," Mr Guterres added.
"I call on world leaders to come together and offer an urgent and coordinated response to this global crisis."
Mr Guterres called on countries to scale up health spending and to help less-prepared nations tackle the crisis, including by supporting the efforts of the World Health Organization.
"A wealthy country must not be convinced that it has only to deal with its own citizens. It's in the interests of a wealthy country to contribute to a global response because the crisis can come from wherever, at any moment," he said.
Mr Guterres said he would take part in the emergency Group of 20 nations summit planned for next week.
"My very strong appeal to the G20 is to have a particular concern with African countries and other countries in the developing world," he told reporters.
"We must absolutely be strong in supporting them because the virus is coming to them and their health systems are extremely weak, so they need very strong support from the developed world and if that support is denied we could have catastrophic consequences," he said, warning millions could die.
He said that when it came to the global economy the liquidity of the financial system must be guaranteed and that banks must use their resilience to support their customers.
"G20 leaders have taken steps to protect their own citizens and economies by waiving interest payments. We must apply that same logic to the most vulnerable countries in our global village and alleviate their debt burden," he added.