The postponement means the airline will also have to push back the first commercial flight using the aircraft, which was scheduled for Feb. 1. The airline had planned to operate flights using the Boeing 777-300ER from Moscow to Bangkok starting Feb. 1, but instead it will use the Boeing 767 and the Airbus A330.
The plane was transferred to the airline Jan. 30 in Seattle.
A spokesman for the Federal Air Transportation Agency said that in accordance with the Air Code, aircraft produced by a foreign manufacturer and transferred for use in Russia must receive certification from the IAC.
"As of now, the IAC has not given Boeing this type of certificate for use of the Boeing 777-300ER aircraft for Aeroflot," he said.
Aeroflot said that it had fulfilled all preliminary legal procedures in a timely manner and that it will "take measures to recover damages."
The Boeing 777-200/300 is certified for use in Russia. Transaero operates nine Boeing 777-200s and four Boeing 777-300s, while a subsidiary of Aeroflot, Orenburg Airlines, operates three Boeing 777-200s.