Syria now views Saudi Arabia as its number one enemy and accuses it of trying to destroy the country by arming jihadists and other rebels fighting to oust President Bashar al-Assad.
The oil-rich Gulf monarchies have sided with the opposition from the start of Syria's conflict in March 2011, with Riyadh leading calls for the fall of Assad.
Syrian Deputy Foreign Minister Faisal Muqdad told AFP this week 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 in an interview on Thursday, referring to the rebels seeking to topple Assad.
"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 rebels, to prevent what he said was "another 11 September incident".
"I think that if the world wants to avoid another 11 September 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 Islamist 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 (Sunni extremist) terrorism tied to Al-Qaeda," the foreign ministry said in a message to UN chief Ban Ki-moon.
It was the first time the Syrian government has appealed to the international body to take action against Riyadh.
"Saudi Arabia is not content to merely send weapons and to finance but also mobilises extremist terrorists and sends them to kill the Syrian people," the Syrian message said.
Saudi-Syrian relations had been tense for years, long before the start of the brutal conflict that has now killed an estimated 126,000 people.
The Sunni-ruled kingdom severed diplomatic relations with Damascus following the February 2005 assassination in Beirut of Lebanese ex-premier Rafiq Hariri who had close ties with Riyadh.
Four years later, diplomatic ties resumed and Assad, who belongs to the Alawite Shiite sect, paid an official visit to Riyadh in March 2009.
