A World Health Organization (WHO) panel declared the ongoing coronavirus outbreak that has killed 213 people a public health emergency of international concern on Thursday.

Tedros Adhanom Ghebreyesus, WHO's director-general, announced the decision after a meeting of its emergency committee, an independent panel of experts, amid mounting evidence of the virus's spread from China to 19 countries — with Italy the latest to report cases.

"Let me be clear, this declaration is not a vote of no confidence in China," Tedros said. "Our greatest concern is the potential for the virus to spread to countries with weaker health systems."

Chinese health authorities raised death toll in the country to 213, while the U.S. State Department issued a "do not travel" warning for China.

The WHO panel, chaired by Didier Houssin of France, is composed of 16 independent experts. Twice last week the experts decided not to declare an emergency while they sought more information from China and awaited evidence of confirmed person-to-person spread of the virus in other countries, so as to meet their criteria for a global emergency.

The United Nations health agency defines an international emergency as an "extraordinary event" that constitutes a risk to other countries and requires a co-ordinated international response. The declaration triggers recommendations to all countries aimed at preventing or reducing cross-border spread of disease, while avoiding unnecessary interference with trade and travel.

It covers temporary recommendations for national health authorities worldwide, which include stepping up their monitoring, preparedness and containment measures.

"This is a wake-up call for the world to pay attention to it," Dr. Michael Gardam, an infectious disease physician in Toronto, told CBC News. "I don't think it changes much what we do here in Canada."

Although the WHO has no legal authority to sanction countries, it could ask governments to provide scientific justification for any travel or trade restrictions that they impose in the event of an international emergency.

A declaration of a public health emergency of international concern — known as a PHEIC in WHO jargon — is rare. Only five have been declared in the past decade: The H1N1 virus that caused an influenza pandemic in 2009, West Africa's Ebola outbreak, polio in 2014, Zika virus in 2016 and the ongoing Ebola outbreak in Congo.

WHO 'very impressed' by China

On Wednesday, WHO's emergencies chief told reporters that China was taking "extraordinary measures in the face of an extraordinary challenge" posed by the coronavirus outbreak.

"We are at an important juncture in this event. We believe these chains of transmission can still be interrupted," said Mike Ryan, executive director of the WHO Health Emergencies Programme who accompanied the body's chief on a trip to China this week.

"They are taking extraordinary measures in the face of what is an extraordinary challenge," he said, referring to China.

The person-to-person spread of the new coronavirus is worrying and would be considered by experts reconvened to consider declaring a global emergency, the WHO said Wednesday. As of Thursday, the countries with such instances include the United States, Germany, Vietnam and Japan.

WATCH | WHO 'very impressed' by China's handling of coronavirus:

The World Health Organization is praising China for its handling of the coronavirus outbreak, calling it 'highly organized.' 1:21

"We are still at a very critical stage in fighting the coronavirus. International solidarity is extremely important and for that purpose all countries should behave in a ... responsible manner," Zhang Jun, China's ambassador to the United Nations, said in response to the WHO declaration.

"While we understand the concerns of other countries, we should also listen to the advice of [the] WHO director-general," Zhang said. "He said he had full confidence in China's efforts."

Zhang noted that it was important to avoid "overreactions, which may result in spillover negative effects."

As of Jan. 30, about 99 per cent of the more than 7,700 cases are in China. Ryan estimated the death rate of the new virus at two per cent, but said the figure was very preliminary. With fluctuating numbers of cases and deaths, scientists are only able to produce a rough estimate of the fatality rate, and it's likely many milder cases of the virus are being missed.

WATCH | Declaring public health emergency could prevent further coronavirus outbreaks:

Declaring an international public health emergency will help co-ordinate resources to try to prevent further coronavirus oubtreaks, the World Health Organization announced Thursday. 4:26

In comparison, the SARS virus killed about 10 per cent of people who caught it.

"While this is likely more contagious than SARS, it's not nearly as contagious as influenza or we'd already have it widespread here in Canada," Gardam said. "The mortality rate of two per cent looks very scary, but we know that's going to drop.

"So this is not as dangerous as SARS was and it's not as contagious as influenza."

The WHO director-general said that during his meeting with Chinese President Xi Jinping, he was "was very encouraged and impressed by the president's detailed knowledge of the outbreak and his personal involvement in the outbreak. This, for me, is real leadership."

Tedros, asked about an international team to be sent to China, said it would be composed of WHO staff, and countries should make "bilateral arrangements" to send their own experts.