"We think that it is inadmissible and dangerous to impose from outside any decisions upon the Syrian people," Peskov told reporters.
He reiterated that Russian President Vladimir Putin had repeatedly stressed that it was upon Syria to decide on the country's future.
Peskov also noted that the same view had been expressed by UN Secretary-General Ban Ki-moon
Syria has been engulfed in a civil war since 2011. Apart from countering the so-called moderate opposition, Syrian government forces are fighting against militants from extremist groups including Islamic State and the Nusra Front, an al-Qaeda affiliate in the country.
Since the start of the conflict, the United States and some of its allies have supported the moderate Syrian rebels while calling for the current president's resignation.
Russia stands for the peaceful conflict-resolution, having hosted two rounds of intra-Syrian peace talks this year in an attempt to promote dialogue between the government and the opposition.
