"Russia notified the US via the Nuclear Risk Reduction Center. We will continue to monitor the situation," the official said.
Earlier in the day, the Russian Defense Ministry said Russia had carried out a combat training launch of a Yars ICBM from the Plesetsk Cosmodrome.
Training combat units arrived at the designated area at the Kura test range on the Kamchatka Peninsula for the launch, the ministry noted.
The ministry said the purpose of the launch was to confirm the tactical, technical and flight characteristics of the missile, which were all completed.