Russian S-300 systems were deployed in Syria following leaks about possible strikes on Syrian airbases, Russian Foreign Ministry's official spokeswoman Maria Zakharova said on Friday.

"First, S-400 systems have been there for a long time and this fact was taken calmly, no one said it was for a show," she said in an interview with the Dozhd TV channel.

"S-300 systems were deployed following leaks from experts close to the United States’ officials that cruise missiles could be used to bomb Syrian airbases, and these leaks probably were not groundless."

"Taking into account the fact that our aerospace force is conducting an operation and our systems are deployed there, no one knows were a missile might fly. That’s why, an S-300 system was deployed," she said.