The World Health Organization warned Thursday that too many countries were not taking all the steps needed to fight the spread of the deadly new coronavirus.

WHO chief Tedros Adhanom Ghebreyesus told reporters in Geneva he was concerned that a "long list" of countries were not showing "the level of political commitment" needed to "match the level of the threat we all face."

"This is not a drill," he said. More than 95,000 people have been infected and over 3,200 have died worldwide from the virus, which by Thursday had reached more than 80 countries and territories.

Most deaths and infections are in China, where the virus first emerged late last year, prompting the country to quarantine entire cities, temporarily shut factories and close schools indefinitely.

But it has quickly spread beyond China's borders. "This epidemic is a threat for every country, rich and poor," Tedros said, warning that "even the high-income countries should expect surprises."

He lamented that a number of countries did not appear to be taking the threat seriously enough, with many relegating the handling of the crisis to their health ministries.

That approach is "wrong", he said, pointing out that the crisis was affecting all parts of society, calling for a "whole of government approach."

He called on the heads of government in every country to take charge of the response and "coordinate all sectors."

What is needed, he said, is "aggressive preparedness."

Tedros rejected the assertion by some that the outbreak has reached pandemic proportions, insisting: "We are not yet there."

He said containing the outbreak was still possible and that that should be the main focus of the response.

"This is not a time to give up. This is not a time for excuses," he said.

"This is a time for pulling out all the stops."