The Astana talks are being brokered by Syrian President Bashar al-Assad's ally Russian Federation and rebel backer Turkey, which are all key players in the conflict.
Muslit, however, said the opposition had yet to receive an agenda for the upcoming negotiations.
The latest diplomacy effort was launched with Russian and Turkish support after regime forces, helped by the Russian air force and Iranian-backed Shia jihadists, defeated opposition factions in eastern Aleppo in December - their biggest setback of the war.
Assad has previously ruled out that idea. Turkey insists the agenda in Astana meetings should be limited to talks aiming to consolidate the cease-fire in the war-torn country, monitor the truce and determine measures against cease-fire violations.
"A second worldwide meeting on Syria is due in Astana these days", Zakharova said.
Flynn Denied Discussing Sanctions With Russia. New Reports Say He Did
The New York Times' report on this added , "Federal officials who have read the transcript of the call were surprised by Mr. That would suggest that Flynn finally realized that tapes proving these discussions occurred might exist.
De Mistura, speaking in Rome, said the United Nations resolution 2254 was based on three main points: establishing governance, coming up with a new constitution, and moving to elections under United Nations supervision.
"That is the agenda and we will not change it, otherwise we open up a Pandora's box", said de Mistura, whose attempts to apply the same agenda to talks past year drew a sharp rebuke from Damascus. The Syrian government said on February 13 it was ready to agree on prisoner swaps with rebel groups.
Elsewhere in his remarks, Muslit said the HNC sought to start the negotiations by discussing a governing body to oversee what he said was a transition of power.
A new round of Syria peace talks in the Kazakh capital Astana - led by Russia, Turkey and Iran and scheduled to begin 15 February - are being delayed by a day due to unexplained "technical reasons", the Kazakh foreign affairs ministry said on Wednesday.