Men run at a site hit by airstrikes in the rebel held besieged Douma neighbourhood of Damascus, Syria February 19, 2017. [Photo/Agencies]

GENEVA - The UN Special Envoy for Syria said Wednesday that though he doesn't expect a breakthrough in the latest round of peace talks set to kick off on Thursday, he hopes the upcoming meetings will pave the way for future negotiations seeking to broker a political end to the five-year conflict.

"Tomorrow morning we will have bilateral meetings with those who have been coming. In the afternoon I plan to have the first opportunity to give and express my welcome to them, hopefully also in the presence of the international support group," Staffan de Mistura told press here.

"I'm not expecting an immediate breakthrough from this round of negotiations but the beginning of a series of rounds that should enable to go much more in depth on the substantive issues that are required for a political solution in Syria," he added.

The diplomat said that he will meet with participants to discuss how to proceed, and that subsequent talks will be guided by UN Security Council Resolution 2254.

He also confirmed that Russia has formally requested that the government of Syria silence its own skies during the talks in a bid to give negotiations the maximum chance of success.

The upkeep of a fragile ceasefire, and the improvement of humanitarian access in the war-torn country are both seen as key factors to talks involving representatives of the Syrian government and rebel factions seeking to oust Syrian President Bashar al-Assad.

While these factors remain unchanged from the past rounds, De Mistura reminded that upcoming talks will be set in a very different context to that in which past negotiations took place.

"2017, from a geopolitical, military and from a general point of view, is very different than 2016," he explained.

"We have seen that what was a ceasefire led by the United States and Russia has now been replaced by two guarantors plus one Iran, called Turkey and Russia. In other words, we are in 2017," he added.

The last time warring parties convened in Geneva was in April last year, a month which saw talks being put on hold amid a humanitarian meltdown and systemic violence in the middle east country.

Since the Syria conflict began in March 2011, an estimated 400,000 people have lost their lives, with millions forced to flee their homes.