UNITED NATIONS, March 13 (Xinhua) -- UN Secretary-General Antonio Guterres on Friday asked the world to declare war on COVID-19, two days after the World Health Organization (WHO) characterized the situation as a pandemic.

"We must declare war on this virus," said Guterres in a video message.

"That means countries have a responsibility to gear up, step up and scale up -- by implementing effective containment strategies, by activating and enhancing emergency response systems, by dramatically increasing testing capacity and care for patients, by readying hospitals ... and by developing life-saving medical interventions," he said.

In addition to being a public health crisis, the virus is infecting the global economy, he said.

Financial markets have been hard-hit by the uncertainty; global supply chains have been disrupted; investment and consumer demand have plunged, with a real and rising risk of a global recession, he warned.

UN economists estimate that the coronavirus crisis could cost the global economy at least 1 trillion U.S. dollars this year, or more, Guterres said, but warning against panic.

"This is a time for prudence, not panic; science, not stigma; facts, not fear. Even though the situation has been classified as a pandemic, it is one we can control," he said.

"We can slow down transmissions, prevent infections and save lives. But that will take unprecedented personal, national and international action," he said.