Rospotrebnadzor, the federal agency responsible for consumer protection and human well-being, announced that it had reported the strain, named AH5N8, to the World Health Organization (WHO) "several days ago" after officials became "absolutely certain" of the results.
Russia's public health chief Anna Popova said there was no sign of transmission from human to human so far.
"Only time will tell how soon future mutations will allow it to overcome this barrier," she said, adding that authorities have sent the WHO information on the seven infected workers at a poultry farm in southern Russia during an outbreak in December.
"This situation did not develop further," Popova said, adding that the workers feel fine now.
The discovery of AH5N8 now "gives us all, the whole world, time to prepare for possible mutations and the possibility to react in a timely way and develop test systems and vaccines," she said.
The WHO has warned that though human transmission of A(H5) viruses is "rare" and generally occurs in people exposed to sick or dead infected birds or their environments, it can "lead to severe illness or death in humans."
In a 2016 statement, the WHO said six of 14 cases of H5N6 avian flu in humans reported since 2014 were fatal.