Russia will not deliver fighter planes or other new weapons to Syria while the situation there remains unresolved, the deputy director of a body that supervises the country's arms trade was quoted as saying on Monday.
"While the situation in Syria is unstable, there will be no new deliveries of arms there," Vyacheslav Dzirkaln told journalists at the Farnborough Airshow in Britain, Russia's Interfax news agency reported.
The refusal to send more arms to Syria could signal the strongest move yet by Moscow to distance itself from Syrian President Bashar al-Assad whom it has defended in the U.N. Security Council from harsher sanctions.
It could also scuttle up to $4 billion of outstanding contracts, including fighter jets and air defense systems which were expected to be delivered this year.
A spokesman for Dzirkaln's Federal Service for Military Technical Co-operation would not confirm the deputy director's comments when contacted by telephone. Reuters was awaiting for a response to requested written questions.
Although completely legal, Russia's arms trade with Syria has fuelled concerns that Moscow is supplying Assad with weapons that are being used against protesters taking part in an armed uprising against him.
Russian President Vladimir Putin has said the arms that his country delivers cannot be used in civil conflicts and Foreign Minister Sergei Lavrov has said the supplies are defensive weapons sold in contracts signed long ago.
But U.S. Secretary of State Hillary Clinton has said Russian statements that the weapons are unrelated to the violence in Syria are "patently untrue" and Washington has described the delivery of a heavy Russian weapons shipment as "reprehensible".
Dzirkaln was quoted as saying Russia, one of Syria's main weapons suppliers, would not be delivering a shipment of 36 Yak-130 fighter planes, a contract for which was reportedly signed at the end of last year.
"In the current situation talking about deliveries of airplanes to Syria is premature," he said.
Rosoboronexport, Russia's monopoly arms exporter, would not comment on Dzirkaln's remarks that Russia was suspending arms deliveries to Syria, which were also reported by Russian news agency RIA.
"We understand the position of (the agency), but we are a separate organization and will not comment," said spokesman Vyacheslav Davidenko.
Syria's arms trade ties with Moscow date back to the Soviet era. It has previously signed contracts worth billions of dollars and hosts a Mediterranean supply-and-repair facility that is Russia's only naval base outside the former Soviet Union.
However a Russian analyst said Moscow had already distanced itself from Assad.
"Russia has stopped signing new contracts with Syria and is delaying the shipments of already signed contracts," Ruslan Aliyev, an expert on the Russian-Syria arms trade at Moscow-based defense think-tank CAST, told Reuters on Monday.
"It's basically a political decision based on Moscow's view of Syria."
Last month, Russia came under criticism from the West after allegations from U.S. Secretary of State Hillary Clinton that attack helicopters were on the way from Russia to Syria.
Moscow has said the helicopters were part of an old contract. It said it provided only weaponry that could be used against external aggression.
"Previously, we were fulfilling old contracts, including repairs of the machines. Until the situation stabilizes, we will not carry out any new arms deliveries," Dzirkaln said.