Vietnam's coronavirus epicentre, Ho Chi Minh City, and capital Hanoi must vaccinate all of their adult residents with at least one shot by Sept. 15, the ministry of health said on Sunday.

Vietnam has one of the lowest coronavirus vaccination rates in the region, with only 3.3% of the country's 98 million people fully vaccinated with two shots, and 15.4% with one shot.

The country is battling a worsening COVID-19 outbreak that has infected more than 520,000 people and killed 13,000, the vast majority in the past few months.

Ho Chi Minh City, the country's business hub, accounts for half of the infections and 80% of the fatalities.

The cities must "mobilise all capable forces including private medical facilities, to vaccinate people at full capacity", the ministry said in an emergency dispatch.

Government data showed 88% of Ho Chi Minh City's adult population of 6.97 million have been inoculated with at least one shot. The rate is 53% for Hanoi's adult population of 5.75 million.

The ministry also set the Sept. 15 deadline for the southern industrial provinces of Binh Duong, Dong Nai and Long An to vaccinate all of their adult populations.

It said Ho Chi Minh City, Binh Duong and Long An have been allocated enough vaccine doses for the vaccination drive.

Vietnam has so far received 33 million coronavirus vaccine doses, and it expects to receive 17 million more by the end of this month, the government said late on Sunday.

Vietnam could be facing a lengthy battle against the coronavirus and cannot rely on lockdown and quarantine measures indefinitely, Prime Minister Pham Minh Chinh said last week.