The World Health Organisation has declared the coronavirus epidemic in China now constitutes a public health emergency of international concern.

WHO director-general Tedros Adhanom Ghebreyesus announced the decision after a meeting of its emergency committee, an independent panel of experts, amid mounting evidence of the virus' spread to some 18 countries.

"The main reason for this declaration is not because of what is happening in China, but because of what is happening in other countries," Dr Ghebreyesus told reporters on Thursday.

"Our greatest concern is the potential for the virus to spread to countries with weaker health systems, and which are ill-prepared to deal with it."

Meanwhile, Coronavirus research outside of China will be carried by Australia's federal government agency CSIRO.

Two days after researchers at the Peter Doherty Institute for Infection and Immunity in Melbourne became the first scientists to recreate the virus outside China, CSIRO aims to paint a clearer picture.

The lab-grown virus - which was developed from the first patient diagnosed in Australia - will help with accurately diagnosing the disease around the world.

The CSIRO says it is collaborating both with the Peter Doherty Institute and the University of Queensland, where trials have begun to develop a vaccine.

The research will aim to understand if vaccines developed for the virus work and are safe, with studies to be conducted at CSIRO's high-containment Australian Animal Health Laboratory facility in Geelong.

Last week, WHO said it was "too early" to declare an international public health emergency but on Thursday said action was needed to help countries to prepare for the possibility of it spreading further.

The new virus has now infected more people in China than fell ill during the 2002-2003 severe acute respiratory syndrome (SARS) outbreak.

The number of cases has jumped to more than 8100 globally, surpassing the 5327 people diagnosed with SARS.

The death toll, which rose to 170 on Thursday morning, is lower than the 348 people who died in China from SARS.

The total number of people infected in Australia rose to nine after two new cases were confirmed on Thursday evening.