The move aims to ensure that no suspected cases would leave the isolated areas.
Foreigners' work permits shall be revoked if they are among the suspected cases but fail to comply with quarantine regulations or arbitrarily leave the isolated areas, PM Phuc ordered.
Viet Nam has so far confirmed 16 infection cases, including 13 Vietnamese, one American, and two Chinese.
Earlier on February 13, Vinh Phuc province locked down Son Loi commune in Binh Xuyen district, where eight people have contracted the virus.
The 20-day lockdown, starting on Thursday, was the latest effort by the local authorities to contain the disease after a three-month-old girl tested positive for the virus./.
By Thuy Dung