UN Secretary-General Antonio Guterres sent de Mistura to the two-day talks in the Black Sea resort of Sochi after the UN received Russia's pledge that the outcome of the Sochi talks would be brought to Geneva.
The UN official said there were heated discussion during the Congress, but added it's a completely normal occurrence during democratic negotiations.
On Tuesday, UN Special Envoy for Syria Staffan de Mistura said that participants in the Syrian National Dialogue Congress in Sochi agreed to draw up a constitutional council. The Syrians also asked the United Nations secretary-general to provide assistance in organizing the work of the constitutional commission which mandate will be determined within the framework of the Geneva process.
"The list of the candidates to the Constitutional Commission will be given to Staffan de Mistura".
The establishment of de-escalation zones was agreed to in May between Turkey, which backs groups opposed to Syria's Bashar Assad regime, and Russian Federation and Iran, who support the regime.
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Kenyan media outlets such as Citizen radio and television, NTV and KTN were banned from broadcasting the event. The result of the August general election was annulled following allegations of irregularities.
Ansari added that Iran called on Turkey to urge the different opposition groups to attend the conference, however it appeared that Turkey's influence was limited. The main result of the congress was the decision to establish a constitutional committee.
Lavrov brushed off criticism "from Paris, Washington and several other capitals" that the Congress is not representative enough.
Earlier on Tuesday, the Syrian opposition decided not to participate in the Sochi summit and instead announced that Turkey could do it on its behalf, anonymous diplomatic sources said.
Russia's most senior diplomat directly addressed Le Drian's attempt to juxtapose the goals of the meeting in Sochi against those of the Geneva process.