Muqdad told AFP on Thursday that Saudi Arabia was providing unfettered support for "terrorist groups" in Syria, while other nations had reviewed their positions.

"I think that all those who supported these terrorist groups have the feeling now that they have made big mistakes," Muqdad said.

"The only party who is declaring the full support to the terrorist groups, to al-Qaeda, is Saudi Arabia," he said.

Muqdad urged the world to press Saudi Arabia to halt its support for the terrorists, to prevent what he said was "another September 11 incident".

"I think that if the world wants to avoid another September 11 incident, they must start telling Saudi Arabia 'enough is enough'," he said, referring to al-Qaeda's 2001 attacks on the US.

Earlier this month, Assad's government urged the United Nations to take a stand against Saudi support for extremist groups whose influence has grown on the battlefield.

"We call on the UN Security Council to take the necessary measures to put an end to the unprecedented actions of the Saudi regime, which is supporting Takfiri terrorism tied to al-Qaeda," the foreign ministry said in a message to UN Secretary General Ban Ki-moon.

It was the first time the Syrian government has appealed to the international body to take action against Riyadh.

Syria has been gripped by deadly unrest since 2011. According to reports, the Western powers and their regional allies -- especially Qatar, Saudi Arabia, and Turkey -- are supporting the militants operating inside the country.

The United Nations says more than 120,000 people have been killed and millions displaced due to the turmoil that has gripped Syria for over two years.

The UN has predicted that more than four million other Syrians will be forced out of their homes in 2014 by the escalating conflict in the country.

NTJ/SHI