* Coronavirus' transmission ability getting stronger
* Incubation 1-14 days, infectious during incubation* China confirms 1,975 people infected, 56 dead
* US to evacuate diplomatic staff, citizens from Wuhan
* China imposes temporary nationwide ban on sale of wildlife
Residents of China's Hubei province, where the new coronavirus outbreak was first reported, will be banned from entering Hong Kong from Monday as China tries to halt the rapid spread of the outbreak.
Health authorities around the world are racing to prevent a pandemic after more than 2,000 people were infected in China and 56 have died.
A handful of cases of infection have been reported in other countries, including in Thailand, Australia, the United States and France, but no fatalities have been recorded outside China.
The mayor of Wuhan, at epicentre of the outbreak, said he expected another 1,000 new patients in the city, which was stepping up construction of special hospitals.
The newly identified coronavirus has created alarm because much about it is still unknown, such as how dangerous it is and how easily it spreads between people. It can cause pneumonia, which has been deadly in some cases.
China's National Health Commission Minister Ma Xiaowei said the incubation period for the virus can range from one to 14 days, during which infection can occur, which was not the case with Severe Acute Respiratory Syndrome (SARS).
SARS was a coronavirus that originated in China and killed nearly 800 people globally in 2002 and 2003.
"According to recent clinical information, the virus' ability to spread seems to be getting somewhat stronger," Ma told reporters.
The Lunar New Year holiday, traditionally celebrated by hundreds of millions of Chinese travelling around the country and abroad to see family, began on Friday but has been severely disrupted by the outbreak.
Ma said China would intensify its containment efforts, which have so far included transport and travel curbs and cancellation of big events.
The country may extend the week-long Lunar New Year holiday, state broadcaster CCTV reported, citing a meeting hosted by Chinese premier Li Keqiang.
The virus, believed to have originated late last year in a seafood market in Wuhan that was illegally selling wildlife, has spread to cities including Beijing and Shanghai.
The World Health Organisation this week stopped short of calling the outbreak a global health emergency, but some health experts question whether China can contain the epidemic.
Hong Kong, which has six confirmed cases, will also ban entry from Monday to people who have visited Hubei province in the past 14 days, the city's government said. The rule does not apply to Hong Kong residents.
Hubei's governor on Sunday said he felt "agonised" and responsible for the outbreak.
Wang Xiaodong described the situation as severe and said medical supplies were still tight.
China confirmed 2,051 cases of infection as of 7 p.m. (1100 GMT) on Jan. 26, while the death toll from the virus remained at 56, state broadcaster CCTV reported.
Airports around the world have stepped up screening of passengers from China, although some health officials and experts have questioned the effectiveness of these efforts.
Health officials in Orange County, California, said a third case had been registered in the United States in a traveller from Wuhan, who was in isolation and in good condition.
On Sunday, China temporarily banned nationwide the sale of wildlife in markets, restaurants, and e-commerce platforms. Wild and often poached animals packed together in Chinese markets are blamed as incubators for viruses to evolve and jump the species barrier to humans.
The New York-based Wildlife Conservation Society called on China to make the ban permanent.
The US State Department said it will relocate personnel at its Wuhan consulate to the United States, while Japan was working with China to arrange a charter flight for Japanese nationals to return from Wuhan.
The outbreak has prompted widening curbs on movements within China, with Wuhan, a city of 11 million, on virtual lockdown and transport links all-but severed except for emergency vehicles.
Health authorities in Beijing urged people not to shake hands but instead salute using a traditional cupped-hand gesture. The advice was sent in a text message that went out to mobile phone users in the city on Sunday morning.
Beijing also postponed the reopening of the city's schools and universities after the Lunar New Year holiday, state radio reported. Hong Kong had already delayed the reopening of schools to Feb. 17.
China has called for transparency in managing the crisis, after a cover-up of the spread of the SARS virus eroded public trust, but officials in Wuhan have been criticised for their handling of the current outbreak.
"People in my hometown all suspect the real infected patients number given by authorities," said Violet Li, who lives in the Wuhan district where the seafood market is located.
Illustrating the extend of disruption to life in China, overall passenger travel declined by nearly 29% on Saturday, the first day of the Lunar New Year, from a year earlier, with air passengers down nearly 42%, a transportation ministry official said.
Many cinemas across China were closed with major film premieres postponed.
Cruise operators including Royal Caribbean Cruises, and Costa Cruises said they had cancelled a combined 12 cruises that had been scheduled to embark from Chinese ports before Feb. 2.
Hong Kong Disneyland and the city's Ocean Park were closed on Sunday. Shanghai Disneyland, which expected 100,000 visitors daily through the holiday period, has already closed.
