Syria has approached Moscow with a request to purchase new Sukhoi 30 fighter aircraft as part of Damascus' drive to upgrade its ailing army.
The Sukhoi 30 was developed in 1996 and has been compared with the US-made F15 E Super Eagle.
The Syrian air force's fleet consists of Russian MiG 29 aircraft.
Israeli defense officials believe Syria is endeavoring for a military buildup for fear of a possible confrontation with Israel.
Syria was said to have recently purchased sophisticated anti-tank missiles from Russia.
Last, Israeli media outlets reported that Syria was trying to purchase from Russia the sophisticated S-300 anti-aircraft system.
Should the system reach Damascus, the Israeli Air Force would find it difficult to penetrate the Syrian and Lebanese airspaces.