China's coronavirus has been named officially as COVID-19, with the World Health Organisation (WHO) explaining that it was important to avoid stigma and that other names could be inaccurate.

"We had to find a name that did not refer to a geographical location, an animal, an individual, or group of people," WHO chief Tedros Adhanom Ghebreyesus said in Geneva on Tuesday (local time).

"Having a name matters to prevent the use of other names that can be innacurate or stigmatising."

The name comes from the words "corona", "virus" and "disease". The number 19 represents 2019, the year the virus became a global emergency.

The first vaccine targeting coronavirus could be available in 18 months, "so we have to do everything today using available weapons", Ghebreyesus said.

China's senior medical adviser, Zhong Nanshan, said the outbreak may be over by April, but the WHO has warned of a global threat potentially worse than terrorism.

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"Wake up and consider this virus as public enemy number one," Ghebreyesus told reporters.

As the epidemic squeezed the world's second-biggest economy, Chinese firms struggled to get back to work after the extended Lunar New Year holiday, hundreds of them saying they would need loans running into billions of dollars to stay afloat.

Company layoffs were beginning despite assurances by President Xi Jinping that widespread sackings would be avoided, as supply chains for global firms from car manufacturers to smartphone makers ruptured.

Zhong told Reuters numbers of new cases were falling in some provinces and forecast the epidemic would peak this month.

"I hope this outbreak or this event may be over in something like April," added Zhong, 83, an epidemiologist who won fame for his role in combating an outbreak of Severe Acute Respiratory Syndrome in 2003.

The WHO said on Tuesday 1017 people had died in China where there were 42,708 cases.

Only 319 cases have been confirmed in 24 other countries and territories outside mainland China, with two deaths - one in Hong Kong and the other in the Philippines.

World stocks, which had seen rounds of sell offs due to the impact on China's economy and ripple effects round the world, kept rising towards record highs on Zhong's comments.