President Bashar al-Assad said the success of a military campaign by Russia, Syria and its allies was vital to save the Middle East from destruction, a day after Moscow said it would step up air strikes against Islamic State targets across Syria.
A year-long air campaign by Western and Arab air forces in Syria and Iraq had been counterproductive, Assad said, helping terrorism spread and win new recruits, but a coalition of Syria, Russia, Iran and Iraq could achieve real results.
"It must succeed otherwise we face the destruction of the entire region, not only one or two states," he said in an interview with Iranian television broadcast on Sunday.
Assad was speaking days after Russian jets based in western Syria launched air strikes against targets Moscow has identified as Islamic State bases, but which Assad's opponents say disproportionately hit rival, foreign-backed insurgents.
The United States, France and Britain say the Russian air strikes are aimed at propping up Assad after recent rebel advances. "They are backing the butcher Assad, which is a terrible mistake, for them and the world," British Prime Minister David Cameron said.
Russia said on Sunday its planes flew 20 sorties in Syria and struck 10 Islamic State targets in the previous 24 hours, including a training camp and a suicide-belt factory.
"We have managed to disrupt their control system, the terrorist organization's supply lines, and also caused significant damage to the infrastructure used to prepare acts of terror," Russia's defense ministry said.
Residents in the Syria province of Homs reported air strikes on Sunday they believed were carried out by Russian jets, in an area controlled by factions fighting under the umbrella of the rebel Free Syrian Army, not Islamic State.