Hong Kong will close its doors Tuesday to all arrivals from South Korea except returning city residents in response to the growing coronavirus outbreak, the territory's security chief said.
"Considering the development of the epidemic in South Korea, the Security Bureau will issue a red travel alert," John Lee told reporters Monday.
The notice means anyone who has been in South Korea in the last fortnight will be denied entry to the international finance hub.
Hong Kong residents will be allowed to return, but will have to undergo a fortnight of medical surveillance.
South Korea has so far confirmed more than 800 cases of the novel coronavirus, by far the largest national total outside China, the origin of the disease.
Hong Kong has 79 confirmed cases, two of whom have died.
The city has implemented compulsory quarantine for any arrivals from mainland China, where the epidemic is most heavily concentrated.
The South Korea ban is the first time it has placed restrictions on a country beyond China.
On Monday, Hong Kong's government also said it would charter flights to evacuate residents from Wuhan, the central Chinese city where the epidemic began in late December.
Hundreds of Hong Kongers are still trapped in the city and have been begging for rescue.
Officials said they would prioritise the most vulnerable, such as pregnant women and people needing urgent medical attention.
Last week, Hong Kong evacuated some 200 residents from the Diamond Princess cruise ship off the coast of Japan which had a major outbreak of the virus.
Two of the returnees have since tested positive for the virus.
Passengers have their temperature checked on arrival at Hong Kong International Airport