The United Nations-brokered committee includes 150 delegates, that is, divided equally among President Bashar al-Assad's government, the opposition and civil society.
UN Secretary-General Antonio Guterres on Thursday hailed as a "landmark" the first meeting of a committee comprising Syrian government and opposition negotiators, tasked with amending the war-torn country's constitution.
On Wednesday, the two sides sat face-to-face in Geneva for the launch of the constitutional review committee's work.
"Yesterday's first meeting of the Constitutional Committee was a landmark, a foundation for progress," Guterres told a conference on mediation in Istanbul organized by the Turkish government.
"I hope this will be the first step towards a political solution that will end this tragic chapter in the lives of the Syrian people, also to create the opportunity for all Syrians to return to their places of origin, in safety and dignity, to end their status as refugees," he said.
The United Nations-brokered committee includes 150 delegates, divided equally among President Bashar al-Assad's government, the opposition and civil society.
However, there is little hope that the process can achieve a breakthrough in reaching a political solution to the conflict which has claimed more than 370,000 lives over the past eight years.
Experts have argued that Assad, whose forces have made major gains against the opposition, has little to lose at the talks and will walk away before making any significant compromises.
Guterres also said that he remained "very concerned about the situation in Idlib", a region of around three million residents of whom half are displaced people from other parts of the country. It is the last major rebel bastion in Syria.
Last week Assad said that winning the Idlib front would be key to winning the war and that his troops had completed preparations for an offensive.
Guterres added that he was repeating his "call for maximum restraint, de-escalation and the protection of civilians and civilian infrastructure on all fronts in Syria".