"The deliveries will be made within the deadlines secured in the relevant documents," Vorobyeva said a day after a Russian lawmaker told local radio that S-400 supplies to China got underway.
Vladimir Gutenev later clarified to online media that the S-400 were at the production stage and not at the stage of delivery.
According to the FSMTC, the contract on the delivery of the S-400 to China is expected to be fulfilled by 2020.
Russia is currently discussing a potential deal on S-400 with Turkey.
The S-400 is Russia's newest air defense system, carrying three different types of missiles capable of destroying aerial targets at a short-to-extremely-long range. The weapon is capable of tracking and destroying all existing aerial targets, including ballistic and cruise missiles.