Hong Kong has recorded 14 cases of the virus and has cut flights and train and bus connections to the mainland, but a push is growing for the semi-autonomous Chinese city to close the border completely.
She said border crossings at Lowu and Lok Ma Chau were to be closed at midnight, as well as all ferry services to the mainland.
But journalists asked if the "stronger" measures were in the interests of the people of Hong Kong, given that government figures showed that more than 60 percent of the 11,715 people who arrived in Hong Kong from mainland China on Sunday did so via the three border points that are to remain open.
But the Hong Kong worldwide airport, the Shenzhen Bay border and the Hong Kong-Zhuhai-Macau bridge will still be available for travelers from other parts of China.
Hong Kong announced it was closing all but two land crossings with the Chinese mainland on Monday to slow the spread of a deadly new coronavirus as medics staged strikes calling for the border to be completely sealed.
The Hospital Authority Employees Alliance (HAEA), which has about 18,000 members, said 2,400 workers took part in the strike, despite calls by the government for medical workers not to.
The Chief Executive of Hong Kong, Carrie Lam, has replied that the government will provide enough health equipment for front line health workers to sustain their safety.
A person surnamed Woo claimed he needed to wait longer than common for therapy on Monday, yet claimed he thinks a total border shutdown is required to secure Hong Kong's 7 million individuals from the coronavirus.
The Hong Kong government said on Monday that it posted its first annual decline in gross domestic product previous year, contracting 1.2%, since the global financial crisis a decade ago, making it one of the worst performers in Asia in 2019.
Panic-stricken residents have emptied shelves in major supermarkets, stockpiling meat, rice and cleaning products as fears escalate over the coronavirus.
On an annual basis, the economy contracted 2.9 percent, compared with a revised 2.8 percent in the third quarter.
A team of UBS economists led by Tao Wang told clients on Monday that outbound travel from the mainland to Hong Kong could "decline by 80-90 percent in Q1 and not recover quickly".
In the latest case of coronavirus infection in the city involves a 72-year-old woman with underlying illness who is the mother of the 13th case.