You need to install Flash Player to play this content.
Staffan de Mistura spoke exclusively to the BBC's Lyse Doucet
The
UN mediator in the Syrian conflict, Staffan de Mistura, has told the
BBC he believes there is a fresh opportunity to resolve the country's
crisis.
He said truce measures could succeed because of the common
threat from Islamic State (IS) militants, as well as a growing weariness
with conflict.The UN has called for "freeze zones" to halt fighting and improve aid.
More than 200,000 people have died in Syria's increasingly fragmented civil war, now in its fourth year.
Rebel groups such as IS and the al-Qaeda-aligned Nusra Front have been fighting among themselves, as well as against forces loyal to President Bashar al-Assad.
Common enemy Syria's conflict has broadened this year, with a US-led coalition now carrying out air strikes against IS fighters and positions.
Speaking to the BBC's Lyse Doucet in the war-torn Syrian city of Homs, Mr de Mistura said the rise of IS was "a new factor which can turn into the possibility of looking at this conflict in a different way".
Mr de Mistura said rival sides that viewed IS and the Nusra Front as a common enemy were beginning to question if the conflict was "giving an opportunity to someone else to take advantage of it".
Moreover, he said, there was a growing realisation that attempts to win the conflict by force were not working and that the only losers in the war were the Syrian people.


The UN envoy was interviewed by the BBC during a visit to the city of Homs
The job of Syria's UN envoy has long been called "mission
impossible." The task was to be available, with a plan, if and when all
sides were ready to listen. On a visit to Aleppo this week, some observers told us some warring parties may now be willing to consider a way out of this crisis. But Syrian troops are now encircling the last rebel held areas in eastern Aleppo to cut off supply lines. It is a siege tactic used time and again in this war.
There is infighting among rebel forces. Mr de Mistura boldly chose this "iconic" city for the first "freeze" to send a strong political message to fighters and a message of hope to Syrians.
President Assad's initial response is unusually positive. But all sides will only agree to a "freeze" if they're prepared to accept a status quo, however temporary. And for the government, that means a plan that consolidates their hold.

"Saying having a peace plan would be ambitious and delusionary," Mr de Mistura told the BBC. "But I do have an action plan, and the action plan starts from the ground - stop the fighting, reduce the violence."
"Everybody agrees there is no military solution," he said, "[but] there is a political solution - let's find it."

Aleppo has been racked by fighting since
July 2012 and for the past year it has witnessed almost daily government
air force raids
Humanitarian aid
Mr de Mistura said that the peace process should be pushed
from "the bottom up" as was happening in the war-ravaged northern city
of Aleppo. He said that first it was necessary to organise a freeze on fighting, then provide more humanitarian aid and then encourage local political dialogue.
Earlier, Mr Assad said his government was considering the UN truce plan for Aleppo, which is split into rebel and government-controlled areas.
Mr de Mistura discussed the plans with Mr Assad during talks in the Syrian capital, Damascus, during the envoy's second visit to the country since his appointment in July.

Mr de Mistura said that local ceasefires or 'incremental freeze zones' were a good way of advancing the peace process
Local ceasefires or "incremental freeze zones" have had some effect in other areas of Syria.The state news agency Sana quoted Mr Assad's office as saying that the president "considered the de Mistura initiative worth studying and trying to work on in order to attain its aims to return security to the city of Aleppo".
Aleppo has been racked by fighting since July 2012. For the past year it has witnessed almost daily government air force raids, with many civilian casualties.
Previous UN envoys have failed to negotiate a full ceasefire between the government and rebel groups.
