It said in a press release Tuesday night that it needs to "review procedures and regulations related to aircraft insurance and flight operations to Russia."
It will refund passengers who have bought tickets or change their tickets to other flights.
Vietnam Airlines, the only Vietnamese carrier to fly to Russia now, added it is working hard with relevant authorities to resume flights as soon as possible.
The airline only resumed the service in January after a two-year hiatus due to Covid-19.
Russian forces launched its attack in Ukraine nearly a month ago and bombarded many parts of the country with artillery and cruise missiles.