The World Health Organization (WHO) says there is a "window of opportunity" to stop the deadly new coronavirus becoming a broader global crisis.
Director-General Tedros Adhanom Ghebreyesus said the steps China took to fight the virus at its epicentre were a good way of stopping its spread.
The praise comes as Chinese officials have been widely criticised for their initial handling of the outbreak.
On Tuesday alone, nearly 4,000 new cases were confirmed in the country.
The death toll has now risen to 490, an increase of 65 deaths in mainland China in one day, the latest figures from the country's National Health Commission (NHC) said. All the new fatalities were in Hubei province, the centre of the outbreak.
In China alone, there are now more than 24,300 cases, with a much smaller number of cases in other countries around the globe.
Two people have died of the disease outside of mainland China - one in Hong Kong and one in the Philippines.
The WHO has declared a global health emergency over the outbreak but said it did not yet constitute a "pandemic", or the worldwide spread of a new disease.
About 80% of those who died were over the age of 60, and 75% of them had pre-existing health conditions such as cardiovascular diseases and diabetes, according to the NHC.
The new coronavirus causes severe acute respiratory infection and symptoms usually start with a fever, followed by a dry cough. Most people infected are likely to fully recover - just as they would from a flu.
What did the WHO say?
Speaking at a technical briefing in Geneva, Dr Tedros praised the Chinese authorities for their response at the epicentre of the outbreak, where millions of people are on lockdown and severe transport restrictions have been imposed.
"There is a window of opportunity because of the high measures, the strong measures China is taking at the epicentre, at the source. So let's use this opportunity to prevent further spread and control it," he said, stressing that developed countries were failing to share data.
The comments come a day after China's top leadership admitted "shortcomings and deficiencies" in the country's response. The government has also been accused of downplaying the severity of the virus at the start of the outbreak and in some cases, attempting to keep news of it secret.
One doctor in Wuhan who tried to warn his fellow colleagues late last year was accused of "making false comments" and told by police to stop the "illegal activity".
Dr Tedros also reiterated his call for countries not to impose travel and trade restrictions, saying 22 nations had officially reported such measures. He urged them to be "short in duration, proportionate" and reviewed regularly.
But Chen Xu, China's ambassador to the UN in Geneva, said some restrictions went against the WHO's advice and told countries not to over-react.
What's the latest around the world?
Earlier, Sylvie Briand, head of WHO's Global Infectious Hazard Preparedness division, said the outbreak "currently" was not a pandemic. While more than two dozen nations have reported cases there have been no confirmations across Africa or Latin America.
Dr Briand also stressed the importance of tackling unfounded rumours, saying they could be an "obstacle for good response and hamper effective implementation of counter-measures".
Meanwhile, 27 cases of human-to-human infections have occurred in nine countries outside China, according to the WHO.
Among other developments:
- In Japan, health officials screened about 3,700 people on board a cruise ship after a passenger tested positive for the virus, discovering a further 10 new cases in the process
- The UK and French governments told their citizens in China to leave the country if they could, with the British Foreign Office saying it will charter another special flight on Sunday
- Taiwan said that from Friday it would deny entry to all foreign nationals who had been to mainland China in the past 14 days
- Macau - a special administrative region of China and one of Asia's biggest gambling hubs - announced that it would temporarily close down all its casinos
How fast is it spreading?
Estimates by the University of Hong Kong suggest the total number of cases could be far higher than official figures.
Dr David Heymann, who led the WHO's response to the outbreak of Sars, or Severe Acute Respiratory Syndrome, in 2002-03, told the Associated Press news agency that the new coronavirus appeared to still be on the increase, and that it was too early to estimate when it would peak.