Iran's foreign minister Mohammad Javad Zarif said that without his country's support for Syria's Assad "legitimate" government, Islamic State (IS) group would have taken over Damascus.
Responding to claims of Iran's support for the Assad regime and how that had prolonged the Syrian crisis, Zarif said Iran still favours a political solution to the Syrian crisis.
"Our support has protected Damascus from Islamic State," Iran's Fars news agency quoted Zarif as telling German news magazine Der Spiegel on Sunday.
He further underlined that the stalemate in the Syrian crisis and the continuous massacres "come from the parties setting preconditions for dialogue".
To counter the Islamic State in Iraq, he said that Iran already cooperates with the Iraqi government, stressing his country's willingness to cooperate with all the countries in the region to counter the militant group.
Meanwhile, on the possibility of cooperating with the US, Zarif said that Iran does not see actual US willingness to counter IS.
The Syrian conflict broke out in 2011 when the opponents of the Assad regime started protesting against the government before the regime began to crackdown brutally on dissent. Opposition groups took up arms in response.