It said every country must be ready for its first case, its first cluster, the first evidence of community transmission and for dealing with sustained community transmission.

Dr Tedros Adhanom, WHO Director-General gave the advice in his opening remarks at the media briefing on COVID-19.

He said all countries must be preparing for all of those scenarios at the same time.

He said, "no country should assume it won't get a cases. That could be a fatal mistake, quite literally," adding "this virus does not respect borders.

"It does not distinguish between races or ethnicities. It has no regard for a country's GDP or level of development."

Dr Adhanom stressed that the point was not only to prevent cases from arriving on the shores of countries, but what they would do when they record cases.

He said although the situation was not hopeless or defenseless, there were things that every country and every person could do to prevent the spread of the disease.

He advised all countries to maintain high surveillance systems for prevention, management, treatment and the spread of the disease by ensuring strong isolation systems, contact tracing, providing quality clinical care, the prevention of hospital outbreaks and community transmission.

The WHO Director-General further urged countries to ensure that their isolation units had enough medical oxygen, ventilators and other vital equipment, as well as the right chemicals for laboratory testing of patient samples among others.

"You must intensify public education and provide the right information on the symptoms of the disease," saying it is not usually a runny nose, but in 90 per cent of cases it's a fever and in 70 per cent of cases a dry cough.

He urged countries to prepare to fight rumours, and misinformation with clear and simple messages that people could understand, and mobilise stakeholder support to fight this outbreak.

Dr Adhanom said even developed countries could be surprised and advised countries to be mindful of the fact that this virus had pandemic potential and WHO was providing the tools to help every country to prepare accordingly.

He said, as of 06:00 hours Geneva time this morning, China had reported a total of 78,630 cases of COVID-19 to WHO, including 2747 deaths, but then it was what was happening in the rest of the world that was now of the greatest concern.

Outside China, there are now 3,474 cases in 44 countries, and 54 deaths, saying "we are at a decisive point," however for the past two days, the number of new cases reported in the rest of the world have exceeded the number of new cases in China.

In the past 24 hours, seven countries have reported cases for the first time: Brazil, Georgia, Greece, North Macedonia, Norway, Pakistan and Romania.

"My message to each of these countries is: this is your window of opportunity. If you act aggressively now, you can contain this virus. You can prevent people getting sick. You can save lives. So my advice to these countries is to move swiftly," he said.

He said the epidemics in the Islamic Republic of Iran, Italy and the Republic of Korea demonstrate what this virus is capable of.

"We've shipped testing kits to 57 countries and personal protective equipment to 85 countries who need it, adding that WHO has also trained more than 80,000 health workers through its online courses, in multiple languages.

 "We've issued operational guidelines, with concrete actions countries can take in eight key areas to prevent, detect and manage cases," he added.

He said the guidelines also included key performance indicators, and the estimated resources needed to prepare for and respond to a cluster of up to 100 cases, saying this was not enough, "so we will do more".

He said WHO stands ready to support every country to develop its national plan, and reiterated that this was not a time for fear, but a period for taking action now to prevent infections and save lives.

He said fear and panic doesn't help, saying people could have concerns and be worried, but the most important thing was to calm down and do the right things to fight this very dangerous virus.