Syria's Assad Says British Airstrikes Against ISIS Will Fail

British airstrikes in Syria against the Islamic State group are illegal and doomed to fail, Syrian President Bashar Assad said in remarks published Sunday.

Assad said in an interview with Britain's Sunday Times that IS cannot be defeated with airstrikes alone unless there is coordination with forces on the ground. His comments were carried by Syrian state news agency SANA on Sunday.

British warplanes began launching airstrikes in Syria on Thursday, hours after Parliament voted to authorize air attacks against IS targets there.

Assad has said the only airstrikes that have worked against IS are those carried out by Russia, which is cooperating with Syrian government forces. Syrian troops have captured areas from IS since Moscow began its air campaign on Sept. 30.

Assad mocked British Prime Minister David Cameron's claims that there are 70,000 moderate Syrian rebels on the ground.

"Let me be frank and blunt about this. This is a new episode in a long series of David Cameron's classical farce, to be very frank. This is not acceptable. Where are they? Where are the 70,000 thousand moderates that he is talking about?" Assad asked.

"That is what they always talk about: moderate groups in Syria. This is a farce based on offering the public factoids instead of facts," Assad said in the interview, which was conducted before the British Parliament authorized the attacks.

Speaking about the British airstrikes, Assad said they "will be harmful and illegal, and it will support terrorism as what happened after the coalition started its operation." Assad was referring to the U.S.-led coalition that began launching airstrikes against IS in Syria in September 2014. IS has lost territory in northern and central Syria since those strikes began, while expanding into other parts of the country.

"This is like a cancer. You cannot cut the cancer. You have to extract it," Assad said.

He said next week's meeting of Syrian opposition and rebel groups in Saudi Arabia ahead of peace talks with the government "will not change anything on the ground."

"Before the meeting and after the meeting Saudi Arabia has been supporting terrorists and will continue to do so," said Assad, whose government refers to all the armed opposition as "terrorists."

Saudi Arabia has been one of the strongest backers of groups trying to remove Assad from power since the conflict began in March 2011, while its archrival Iran has provided key support to his government.

Ali Akbar Velayati, a top adviser to Iran's Supreme Leader Ayatollah Ali Khamenei, said Assad is "Iran's red line." His comments were broadcast on state TV Sunday.

"Iran has no intention to leave Assad alone," he added.