Russian sources are now disputing the claims of S-300 delivery by Assad.
A spokesperson told the Guardian that the foreign ministry was preparing to issue an official statement on the S-300 delivery, but would not disclose when it would be released.
Syria 'will not receive Russian S-300 missiles for at least a year' | World news | guardian.co.uk
Russia unlikely to send S-300 missiles to Syria before autumn - Interfax | Reuters
Syrian contract for upgraded MiG-29s.
Russian arms manufacturer signs contract to sell at least 10 MiG fighter jets to Syria - The Washington Post