A U.N. official is calling for more time to give diplomacy a chance in Idlib, the last rebel-held area in northeastern Syria.
The U.N. Senior Adviser for Syria, Jan Egeland, warns that a government military offensive to retake the province could risk the lives of 3 million civilians who have nowhere to run.
Egeland says he is relieved a Russian-Turkish agreement on Idlib is holding, despite the failure of militants and rebels to meet a deadline for their withdrawal from a buffer zone separating them from government forces.
Although the situation remains calm in the area, Egeland says there are worrying reports that armed groups are building fortifications inside Idlib. He says there are signals a conflict may engulf parts or most of the province.
Both Russia and Turkey have indicated more time will be given to implement the agreement.
"That is a great relief to us because if one is to follow a military logic that has too often been followed in this war alone, it would be horrific news. Not only for civilians, but also for humanitarians of whom there are 12,000 colleagues in Idlib," Egeland said.
While it is unclear where the fighters and their heavy guns would upon leaving the buffer zone, Egeland says it is likely they would go back to Idlib, which could trigger war.
He warns that the catastrophe that would result from a war in Idlib could be the worst in the seven-year civil war. More than 350,000 people reportedly have been killed since the Syrian conflict began in 2011.