Syrian President Bashar al-Assad said the West is "crying" for refugees flooding into Europe but its support for "terrorists" in his country lies at the roots of the crisis.

In an interview with Russian media, Assad also said it was natural for Iran to have stepped up its decades-old military and economic support for Damascus at a time of war.

"Those refugees left Syria because of the terrorism, mainly because of the terrorists and because of the killing, and second because of the results of terrorism," said the embattled leader.

"When you have terrorism, and you have the destruction of the infrastructure, you won't have the basic needs of living," Assad said, according to a transcript made available on Wednesday.

"So, the West is crying for them, and the West is supporting terrorists since the beginning of the crisis when it said that this was a peaceful uprising," said Assad.

"If you are worried about them, stop supporting terrorists ... This is the core of the whole issue of refugees."

Syria's government labels all those involved in the anti-Assad uprising and ensuing civil war as "terrorists", including Western-backed rebels.

Assad told the media outlets from Russia, a major ally, that Tehran's support was also essential for his regime in Syria's conflict, which has cost more than 240,000 lives since 2011.

"Iran supports Syria and the Syrian people. It stands with the Syrian state politically, economically and militarily," he said.

"When we say militarily, it doesn't mean -- as claimed by some in the Western media -- that Iran has sent an army or armed forces to Syria. That is not true," said Assad.

"It sends us military equipment, and of course there is an exchange of military experts between Syria and Iran," he said.

"This has always been the case, and it is natural for this cooperation to grow between the two countries in a state of war."

With strong ties which date back "three and a half decades", Iran's support is now "essential in this difficult and ferocious war", he said.

Syria was the only Arab state to side with the Islamic republic during its 1980-1988 war against Saddam Hussein's Iraq.

Iranian media run regular reports on fighters killed in the Syrian conflict described as volunteers helping to defend Shiite holy sites in the country.
Source: AFP