"We have said that it is to be a Syrian-led solution, a Syrian owned (solution)," said de Mistura in an interview with France 24 television on Friday.
He added, "Can't we leave the Syrians to actually decide on that? Why should we be saying in advance what should the Syrians say, as long as they have the freedom and the opportunity of saying so?"
De Mistura made the remarks hours after Russian President Vladimir Putin told Western leaders during a conference call Friday that the Syrian government’s decision to hold legislative polls in April does not contradict the peace process.
Earlier, Syrian President Bashar al-Assad set April 13 as the date for the parliamentary elections in Syria. The last parliamentarian elections were held in 2012, just months after the adoption of a new constitution in the war-torn country.
The presidential decision to hold the vote came just hours after Russia and the US agreed to enforce a cessation of hostilities starting from February 27.
The fragile cessation of hostilities in the five-year conflict is in its seventh day and the United Nations has said it wants to resume peace talks on March 9.