The new Chinese virus which has already spread abroad “is still preventable and controllable”, China says.
Its National Health Commission warned, however, that close monitoring was needed given the source, transmission and mutation methods were unknown.
Two people are known to have died from the respiratory illness which appeared in Wuhan city in December.
In its first statement since the outbreak, the body promised to step up monitoring during the Lunar new year.
Millions of Chinese travel to their families for the holiday – also known as the Spring Festival – beginning next week.
There have been more than 60 confirmed cases of the new coronavirus, but UK experts estimate a figure nearer 1,700.
Singapore and Hong Kong have been screening air passengers from Wuhan, and US authorities have announced similar measures at three major airports in San Francisco, Los Angeles and New York.
While the outbreak is centred on the central Chinese city of Wuhan, there have been two cases in Thailand and one in Japan.
Chinese officials say there have been no cases of the virus spreading from one person to another.
Instead, they say, the virus has crossed the species barrier and come from infected animals at a seafood and wildlife market in Wuhan.
The WHO’s China office said the analysis was helpful and would help officials plan the response to the outbreak.