A resolution it issued Wednesday says the doses will be procured by a contractor it will choose under provisions for "special cases" in the Law on Bidding.
It also says the number of doses bought and donated to the country this year will exceed the number specified in a previous resolution of around 150 million.
The Ministry of Health has been tasked with "swiftly" buying the vaccine from Hungary.
Last month the government decided to buy 20 million doses of China’s Vero Cell vaccine at more than VND3.2 trillion ($142 million) and five million doses of Cuba’s Abdala at VND742 billion ($32.6 million).
The money will be drawn from the Covid-19 vaccine fund established to raise donations.
The fund website says it had raised more than VND8.692 trillion as of Wednesday.
So far 52.2 million doses of various vaccines have arrived, 35.9 million people have been vaccinated, 12.2 million of them twice.