"If Geneva's target is to construct a new democratic secular regime in Damascus, all parties and all sides to the Syrian conflict should be invited along with the government and the civil society," Ahmad said.
He stressed that no opposition group inside or outside of Syria could be excluded, "including Kurds, for example, just because Turks or Saudis do not want to invite them."
Syria has been mired in a civil war since 2011, with government forces loyal to President Bashar Assad fighting a number of opposition factions and extremist groups.
In December, the UN Security Council adopted a resolution on Syrian settlement, which reaffirmed the goals of the Vienna agreements to bring the entire spectrum of political groups in the crisis-torn country to the negotiating table and stated that the next round of the talks would take place in January, 2016.
Turkey has strongly opposed the inclusion of the Kurdish Democratic Union Party (PYD) in the reconciliation talks. Turkish President Recep Tayyip Erdogan and Prime Minister Ahmet Davutoglu reiterated over the weekend that Turkey makes "no distinction" between the PYD and the militant Kurdistan Workers’ Party (PKK), which is outlawed in Turkey.
On Monday, one of the leaders of the Syrian Popular Front for Change and Liberation, Qadri Jamil, told Sputnik it would a few days to decide on the list of participants in the talks.
