A Chinese security guard wears a protective mask as he waits to take temperatures while standing next to a sign instructing people to wear masks, February 12, 2020 in Beijing, China.

There are 44,730 cases in China and at least 1,114 deaths as of Wednesday morning, Tedros said. Outside of China, there are 441 cases across two dozen countries and one death, he said.

"The outbreak could still go in any direction," Tedros Adhanom Ghebreyesus, director-general of WHO, warned at a news conference at the agency's headquarters in Geneva. The slowing number of new cases "must be interpreted with extreme caution."

New coronavirus cases in China appear to have stabilized in recent days, but world health officials cautioned the public against reading too much into those numbers. The outbreak could still get worse, World Health Organization officials said Wednesday.

Dr. Mike Ryan, executive director of WHO's emergencies program, said the slowing in cases is due in large part to "the huge public health operation in China." While new cases appear to have slowed in recent days, Ryan said public health officials must still be vigilant in preparing for the virus to get worse.

"We must continue to stop the virus, while preparing countries for the arrival of the virus," Ryan warned. "I know that sounds contradictory, but it is not a contradiction."

"We hope to see the virus come under control. We are not going to speak about numbers or dates," he added. "It's way too early to try and predict the beginning, the middle or the end."

Ryan said public health officials "have a good view on the virus," adding there are eight cases globally where officials can not find a plausible explanation of how they were exposed to it.

Since emerging in Wuhan in central China about a month ago, the virus has spread from about 300 people as of Jan. 21 to more than 45,000.

World health officials have said the respiratory disease, named COVID-19, is capable of spreading through human-to-human contact, droplets carried through sneezing and coughing and germs left on inanimate objects. Symptoms can include a sore throat, runny nose, fever or pneumonia and can progress to multiple organ failure or death in some severe cases, they said.

Scientists are working on deeper investigations into the source of the outbreak, Tedros said Wednesday. Earlier in the week, WHO officials said the virus that emerged from a seafood market in Wuhan likely originated in bats and then jumped to an "intermediate host" before infecting humans.

Scientists are running tests on various animals, but have so far not found the host responsible for the outbreak, Dr. Sylvie Briand, head of WHO's Global Infectious Hazard Preparedness division, told reporters at the time.