US officials say there are two main problems with Syria's cessation of hostilities. The first is the failure of the Syrian government to respect it, and the second is continued activity by the al-Qaeda-linked al-Nusra Front. Commanders of the opposition forces say they — not al-Nusra — are the main groups fighting to open the only road to their enclave inside Aleppo city. Al Jazeera’s Zeina Khodr reports from Gaziantep, on the Turkey-Syria border. (Courtesy: Al Jazeera)