Harsh desert conditions are hampering Russian warplanes sent to Syria from striking targets and grounding Russian transport aircraft as well, according to a report by USA Today.

Citing a senior US defence official, the report said Moscow's attack planes "are breaking down at a rapid rate that appears to be affecting their ability to strike targets.''

"Nearly one-third of Russian attack planes and half of its transport aircraft are grounded at any time as the harsh, desert conditions take a toll on equipment and crews," said the unnamed official who was not authorised to speak publicly about sensitive intelligence matters.

Richard Aboulafia, an aviation analyst at the Teal Group, an aerospace consulting firm, remarked that the problems of keeping planes in the air could also be a consequence of Russia's inexperience in deploying forces at some distance.

"They could have bad operating procedures, inadequate supplies of spare parts and support crews,'' according to Abuolafia as quoted by USA Today.

"An awful lot of expeditionary warfare revolves around logistics. A lot of it comes down to experience. They don't have that much of it,'' he added.

David Deptula, a retired three-star Air Force general who led planning for the air war in Operation Desert Storm, said he is not surprise with Russia's air situation since they "lack experience being deployed and have been flying their jets hard."

He claimed that Russia's rate for cargo planes was "pretty low.''

"If those rates are accurate, it indicates that their deployed logistics function requires some attention," stressed Deptula.

While acknowledging the "planes break, especially in austere, deployed conditions,'' a senior Air Force commander with multiple combat deployments in the Middle East said a readiness rate of less than 80 percent for US warplanes would already attract attention from top brass.

But he said such mission-readiness rate of less than 80 percent is only a matter of concern, not alarm.

Since September, Russia has deployed its warplanes, including advanced Fullback ground-attack jets, helicopters and troops to a base near Latakia, Syria, in attempts to obliterate Islamic State (ISIS) militants and other combatants fighting the regime of Syrian President Bashar al-Assad.

The Obama administration maintains that Russia's move in Syria was principally meant to prevent Syrian President Bashar Assad from losing power.

"What the Russians are actually doing is buttressing the Assad regime, which, as I have said, will have the effect of fanning the flames of the civil war," said Defense Secretary Ash Carter, adding there were very few strikes that have been directed toward ISIS.

More than 200, 000 people have been killed as a result of the civil war in Syria.

Last week, the Pentagon and Russian military reached an agreement to avoid conflict among pilots flying missions over Syria. On Sunday, Russian lawmakers said Assad would be willing to call early elections but only after the defeat of ISIS, the Associated Press reported.