Saudi Arabia's Prince Turki Al-Faisal on Tuesday blamed the United States and Europe for the rise of the Islamic State (IS).

The former intelligence chief and ambassador to the United States said arming the so-called moderate rebels battling Syrian President Bashar al-Assad when the civil war broke out three years ago would have prevented extremists from filling the void. Faisal said the recent creation of an international coalition to combat the group was a good first step, but that IS cannot be defeated until the world gets behind the Syrian opposition and ousts Assad.

"Had America and Europe listened to the kingdom and provided the moderate opposition with anti-tank, anti-aircraft and artillery weapons, we would not have had to deploy our air forces to face the challenge of [IS]," Faisal said in the keynote address of the annual Arab-US policy conference put together by the National Council on US-Arab Relations. "These terrorists filled the void because of this neglect of the genuine opposition. And while Assad continued to bomb and gas his people, the moderate opposition had to fight on two fronts."

Faisal is often trotted out to declare publicly what current Saudi officials say in private. Last year, he told Al-Monitor in an interview on the sidelines of the NCUSAR conference that there was a "high level of disappointment" with the Barack Obama administration's Syria policy.