The Chinese government says the US has 'spread fear' instead of offering help. Photo: BBC

The Politburo Standing Committee said the national emergency management system had to improve. A crackdown on wildlife markets, where the virus emerged, has been ordered.

By the end of Monday, more than 20,000 cases and 425 deaths had been reported in China - an increase of more than 3,000 confirmed cases in a single day.

On Monday alone, there had been 64 new deaths, China's National Health Commission said - all in Hubei province, where the virus is believed to have originated.

The number of deaths in China, excluding Hong Kong, now exceeds the 349 killed on the mainland in the Severe Acute Respiratory Syndrome (Sars) outbreak of 2002-03.

There are more than 150 cases in other countries, with one death in the Philippines.

The new coronavirus causes severe acute respiratory infection and symptoms usually start with a fever, followed by a dry cough.

The outbreak took its toll on Chinese shares when financial markets reopened on Monday following the Lunar New Year holiday. The Shanghai Composite index closed nearly 8% lower, its biggest daily drop for more than four years.