The U.N. chief said Tuesday that he expects the 150-member committee to work "in good faith." Representatives from the Syrian government, opposition and civil society are to begin meeting in Geneva on Wednesday.
Repeated U.N. efforts to host talks on ending Syria's eight-year civil war have largely failed. Guterres stressed that "meaningful engagement" by committee members must be accompanied by a cessation of hostilities across the country. He says that would facilitate "a broader political process."
Syrian President Bashar Assad's government has all but won the war militarily with the help of Russia. Syria's last rebel stronghold is in the northwestern province of Idlib.