Dinh Viet Son, deputy head of the Civil Aviation Authority of Vietnam, said currently only Vietnam Airlines operates direct flights to Moscow.
Since tensions between Russia and Ukraine have escalated; however, the national flag carrier has for long avoided flying over the airspaces of Ukraine and Belarus.
In addition, flights to the U.K., France and Germany have also dodged the airspaces of Russia and Ukraine.
Therefore, international flights from Vietnam to Europe are still operating normally, Son said.
Currently, Vietnam Airlines and Bamboo Airways have resumed weekly regular flights to Europe.
Russian forces fired missiles at several Ukrainian cities and landed troops on its south coast on Thursday.
Ukraine State Air Traffic Services Enterprise said on its website that the country's airspace was closed to civilian flights starting at 00:45 GMT on Thursday and that air traffic services had been suspended, Reuters reported.
Vietnam has resumed commercial flights to 20 of 28 countries and territories that it operated direct flights to before the pandemic, including Moscow.
The country also ended all restrictions on international flights on Feb. 15 after gradually lifting them since Jan. 1 after almost two years of suspension.