Saudi Arabia has accused the Syrian government of waging "genocide" against rebels and criticised Iran and Hezbollah for backing and arming the regime.

Speaking at a news conference with US Secretary of State John Kerry in Jeddah, Saudi Foreign Minister Prince Saud al-Faisal Saud has said Syria is facing a "double-edged attack".

"(It) is facing a massive flow of weapons to aid and abet that invasion and that genocide. This must end." he said.

Prince Saud also attacked Iranian involvement in the war-torn country and described Tehran's backing foreign militias as "the most dangerous development".

He also repeated Saudi Arabia's call for the rebels to be armed.

Saudi Arabia, a Sunni state which views Shia Iran as its arch-rival, has increased aid to Syrian rebels in recent months, supplying anti-aircraft missiles among other weapons.

At a meeting in the Qataris capital, Doha, on Saturday, ministers from 11 nations in the "Friends of Syria" group agreed "to provide urgently all the necessary material and equipment to the opposition on the ground".

Syrian regime called its neighbours to stop arming rebels battling to overthrow Bashar al-Assad and said a decision by Western and Arab countries on Saturday to arm those rebels would prolong the crisis and deepen the bloodshed.

More than 93,000 people have been killed in Syria since peaceful protests erupted in March 2011. Assad's violent response helped provoke what is now a civil war that has driven nearly 1.7 million refugees into neighbouring countries.