World Health Organization Director-General Tedros Adhanom Ghebreyesus Photograph:( AFP )
The UN health agency's chief also called for greater solidarity, accusing some governments of wealthy countries of being "well behind" in sharing data on virus cases.
The dramatic measures taken by China to rein in the deadly new coronavirus outbreak have prevented significant spread abroad, providing a "window of opportunity" to halt transmission, the World Health Organization said Tuesday.
But the UN health agency's chief also called for greater solidarity, accusing some governments of wealthy countries of being "well behind" in sharing data on virus cases.
Watch: WHO asks nations dealing with Coronavirus to be prepared, not panic
"That doesn't mean that it won't get worse. But for sure we have a window of opportunity to act. Let's not miss this window of opportunity," he said.
Tedros said the WHO had received complete case report forms for only 38 per cent of the cases outside China.
"Some high-income countries are well behind in sharing this vital data with WHO. I don't think it's because they lack capacity," he said.
"Without better data, it's very hard for us to assess how the outbreak is evolving, or what impact it could have, and to ensure we are providing the most appropriate recommendations," he said.
More than 20,400 cases of the virus have been confirmed in China since the virus was first detected on December 31.
The death toll in mainland China has soared to 425 and more than 20 countries have now confirmed cases of the virus, which the WHO has declared a global health emergency.