China's increasingly drastic containment efforts began with the suspension of plane, train and bus links to Wuhan, a city of 11 million people in central China.
As of now, 4,200 confirmed cases of the virus have been reported from China. Hong Kong and Malaysia announced they were barring entry to visitors from Hubei province.
Stock markets around the world were down sharply on Monday as investors anxious the outbreak could hurt the global economy.
China's National Health Commission said 24 more people had died in Hubei province, the centre of the outbreak.
According to the Korea Centers for Disease Control and Prevention (KCDC) on Monday, a 55-year-old South Korean man who returned from the Chinese city of Wuhan on January 20 tested positive for the new strain of virus, raising the number of confirmed cases here to the four.
According to Xinhua news agency, the health authorities earlier on Sunday said that as of Jan 26, there were 2,744 confirmed coronavirus cases in China, 80 people have died, while 51 have been released from hospitals.
On Tuesday, English-proficiency and other tests for students to apply to foreign universities were canceled. Public schools and universities have been ordered to postpone reopening following the Lunar New Year holiday until further notice.
Beijing's official response has "vastly improved" since the 2002-03 SARS outbreak, which also originated in China, but "fears of a global contagion are not put to bed", said Vishnu Varathan at Mizuho Bank in Singapore. More than 40 cases have been confirmed elsewhere in the world.
The fourth patient, who had not shown any signs of illness upon entering the country after returning from a trip to Wuhan, visited a local clinic a day later in Pyeongtaek in southern Gyeonggi Province when he showed signs of a simple cold. Health officials said they had no evidence the virus was spreading in the United States and they believe the risk to Americans remains low.
By the end of Monday, eight confirmed cases had been reported in Hong Kong Special Administrative Region, seven in Macau Special Administrative Region and five in Taiwan.
The epidemic has revived memories of the Sars outbreak that originated in China and killed almost 800 people. The outbreak has also led many stores to shut operations.
Two patients have been discharged from hospitals after treatment, while 63 patients were in stable condition.
China has confirmed more than 2,700 cases of the new virus, most in Wuhan. The first is scheduled to be finished next week.
The coronavirus family includes the common cold but also more severe illnesses like SARS and Middle East Respiratory Syndrome.
Despite enhanced quarantine efforts, concerns are rising here that the Wuhan coronavirus may spread across the country as some patients confirmed to be infected with the virus have not been adequately screened at airports and have been in contact with citizens here. China on Sunday banned trade in wild animals and urged people to stop eating meat from them.