Syrian President Bashar Assad condemned the airstrikes being carried out by a U.S.-led coalition in Syria, and said that Britain and France do not have the capability to defeat terrorism. Speaking to the Sunday Times, he added that the aerial campaign against the Islamic State group, or ISIS, could instead result in the spreading of militancy.

While Assad's regime has been criticized by the West, which has called on him to step down and end the long-drawn Syrian civil war that has killed thousands and rendered millions homeless, the recent emergence of ISIS has triggered an aerial campaign aimed at eliminating the group's activities. Before ISIS' emergence as the dominant rebel group in Syria, Western powers had sought to arm other rebel groups fighting to dethrone Assad.

“We know from the very beginning that Britain and France were the spearheads in supporting the terrorists in Syria,” Assad said, in the interview, adding: “They don’t have the will and they don’t have the vision on how to defeat terrorism.”

On Wednesday, U.K. lawmakers voted to join the U.S.-led coalition against ISIS and the first British warplanes planes bombed strongholds of ISIS in Syria Thursday. The U.S. central command said that, on Friday, coalition forces conducted 11 strikes in Syria and 12 strikes in Iraq against the ISIS targets.

Assad also ridiculed British Prime Minister David Cameron in the interview, referring to his estimate of nearly 70,000 Western-backed opposition fighters in Syria. Cameron had claimed that these fighters could take back territories held by ISIS and the Al Nusra Front as the airstrikes weakened them.

“This is a new episode in a long series of David Cameron’s classical farce, to be very frank. This is not acceptable," Assad said, in the interview.

Assad's comments came a day after an attack at the Leytonstone station in East London where a suspect stabbed three people, yelling “This is for Syria.” The attack is currently being considered as an act of terrorism and police currently have the man in custody. Britain’s decision to join the airstrikes follows the attacks in Paris last month, which killed 130 people. ISIS claimed responsibility for the attack, which also prompted France to declare war on the group.

Last week, an attack on a healthcare center in California claimed 14 lives and authorities are investigating if it was linked to ISIS or its sympathizers. According to data collected by the New York Times, there have been 51 attacks directly linked to ISIS since September 2014. About 40 of those attacks took place in the Middle East, while six took place in the West.

Assad also said that airstrikes alone will not help eliminate ISIS. “They cannot defeat ISIS by airstrikes; they are going to fail again,” Assad said.

When asked if the Syrian government was asking for cooperation from Western countries, Assad said: “They have no respect for international law and we didn’t ask for their cooperation,” adding: “If they are ready, we will welcome them. This is not personal.”

On the other hand, Assad supported the role of Russian airstrikes in the country and said that Moscow’s support is “very important” and that “it has had a significant impact on both the military and political arena in Syria.”

“President [Vladimir] Putin had already taken the step when he said he was willing to create a coalition. My response to this was that we are ready if you want to bring your forces to participate,” Assad said, adding: “I sent President Putin a formal letter and we released a statement announcing that we had invited them to join our efforts.”

Russia began its airstrikes against ISIS in Syria after the group claimed responsibility for the downing of a Russian passenger jet over Egypt last month. However, the West has criticized Russia's actions in Syria as being focused on helping Assad -- a staunch ally of Moscow -- eliminate rebel groups opposed to his regime.

ISIS, which has vowed to create an Islamic caliphate in the Middle East, currently controls over a third of Iraq and Syria.