A Syrian legislator says there will be no presidential vote before Bashar Assad's latest term ends in 2021, after a new Russian proposal for ending the conflict called for early elections.

Sharif Shehadeh told The Associated Press Wednesday that parliamentary elections are an internal Syrian affair, adding that it is still too early to hold them.

His comments came a day after Russia circulated a document on ending Syria's conflict that calls for drafting a new constitution in up to 18 months. The charter would be put to a popular referendum and followed by an early presidential election.

Prominent Syrian opposition figure Haitham al-Maleh said Russia is an "occupation force" in Syria, adding that the opposition will not accept that Assad have any role during a transitional period.