The government said it would make civil servants work from home and urged employers to be flexible with work from home arrangements. Schools would remain closed until further notice, it added.
Hong Kong has 273 confirmed cases of coronavirus, which has killed four people in the city.
On Tuesday, Hong Kong leader Carrie Lam said that all arrivals to the city would be subject to a 14-day quarantine.
Residents were also advised to avoid all non-essential travel.
Hong Kong detected its first cases as early as January, but has managed to avoid the scale of contagion seen in other countries and territories due to severe social distancing measures and a strong community response.
Inmates in Hong Kong prisons have been working night shifts to produce face masks as the outbreak continues.
About 1,200 retired or off-duty prison officers are also working to produce the masks, the government said.
