UN envoy for Syria Staffan de Mistura and top diplomats from the United States, Russia, Iran, China, Saudi Arabia, Turkey, Egypt, Qatar, Lebanon and France are currently discussing a settlement of the Syrian civil war in the Austrian capital Vienna.
"It is important for international powers to agree on details to give the Syrian people opportunity to decide on their future," Jaafari told reporters on the sidelines of a meeting in Vienna.
Earlier in October, Russian President Vladimir Putin stressed that it is the Syrian people who should decide the fate of their country.
Syria has been in a civil war since 2011 as government forces loyal to President Assad fight several opposition and radical Islamist militant groups, including Nusra Front and Islamic State.