Syrian president says IS has grown despite US airstrikes

In the interview with "60 Minutes," which aired on CBS news in the United States on Sunday, Assad said the US airstrikes against IS in Syria which began last September sometimes have a local effect.

"But in general, if you want to talk in terms of ISIS, actually ISIS has expanded since the beginning of the strikes," the president said, using another acronym for IS.

Assad said there were some estimates that Islamic State was attracting 1,000 recruits a month in Syria.

"And Iraq - they are expanding in - in Libya and - many other - al Qaeda affiliate organizations have announced their allegiance to ISIS. So that's the situation," Assad added.

Negotiated settlement

Questioned about the alleged use of chlorine gas and barrel bombs by the Syrian army, Assad said that this was "part of the malicious propaganda against Syria."

"First of all, the chlorine gas is not military gas. You can buy it anywhere," he said.

Washington is currently seeking a negotiated settlement to Syria's civil war which would exclude Assad. US State Department officials recently said Assad will "never" be part of a negotiation to end the Syrian conflict, but that officials from his government could be part of the process.

Open to dialogue

In the interview with journalist Charlie Rose, the Syrian president said that "in principal ... every dialogue is a positive thing."

Assad added, however, that such a dialogue with the US needs to be based on "mutual respect."

Asked in the interview under what circumstances he would leave power, Assad said, "When I don't have the public support. When I don't represent the Syrian interests, and values."

Syria's conflict started in March 2011 with protests against Assad. More than 220,000 people have been killed and almost 4 million have fled the country since then.