The new coronavirus epidemic is at a "decisive point" globally, World Health Organization chief Tedros Adhanom Ghebreyesus said Thursday, urging affected countries to "move swiftly" to contain the disease.

"We're at a decisive point," Tedros told reporters in Geneva.

Pointing to a decline in new cases in China, Tedros said: "It's what's happening in the rest of the world that's now our greatest concern".

Urging countries at the early stages of the outbreak of the COVID-19 disease to "move swiftly", he added: "If you act aggressively now, you can contain this virus, you can prevent people getting sick, you can save lives."

"There does not appear to be widespread community transmission," he added.

Tedros emphasised that all countries should ensure that their health systems were prepared for an outbreak.

"We are actually in a very delicate situation in which the outbreak can go in any direction based on how we handle it," Tedros said.