Syria berated Saudi Arabia Thursday, questioning whether the country is qualified to play a role in resolving the Syrian conflict, a foreshadowing of possible difficulties as representatives from nearly 20 nations arrive to meet in Vienna.

Neither Syria nor its opposition will be present at the Vienna talks, which formally begin Friday. However, as various dignitaries arrived in the Austrian capital, Syria's information minister lashed out at Saudi Arabia, alleging it is not qualified to play a "productive" role in resolving the conflict, citing the conflicts there as well as in Yemen and in Iraq, according to the Associated Press.

Syrian Information Minister Omran al-Zoubi called Saudi Foreign Minister Adel Jubeir a "tumor" and a "servant" who had best keep silent. Conversely, Jubeir said on Wednesday there is no role for Syrian President Bashar al-Assad in any political transition.

Alongside the U.S. and Turkey, the Saudis insist Assad must step down in favour of a unity government and are supporting groups that oppose him, reported AFP. 

Syrian National Coalition member Bassam Abdullah dismissed the talks in Vienna as an attempt to buy time for the military to regain territories from rebels.

Nearly 20 nations have signaled that they will attend but most attention will be focused on the United States, Russia, Iran and Saudi Arabia to see if the foreign ministers of all four nations will be able to work together despite disagreements in Syria and other issues, according to NBC's Boston affiliate WHDH-TV.

The Iranian delegation is led by Foreign Minister Mohammad Javad Zarif, who alongside U.S. Secretary of State John Kerry was a key negotiator in talks that led to the July 14 nuclear deal between Tehran and six world powers after more than a decade of diplomatic efforts.