Syrians have fled to Idlib from other parts of the country as the government has advanced. The United Nations has warned that an offensive could force 2.5 million people towards the Turkish border.
The Deraa offensive marks endgame for the Syrian rebellion – but strife in Syria is set to persist.
Years after a no-fly zone for Aleppo failed to gain Western sympathy, the Afrin pleas will likely fall on deaf ears.
Syria's army and its allies have increasingly pushed for such evacuation deals for rebel enclaves near big cities or in other strategic locations after long periods of siege and bombardment.
The Syrian army, backed by local militias a financed and equipped by Iran, have been escalating a fierce assault against Sunni rebels in an enclave in the foothills of Mount Hermon.
US-led coalition forces, Syrian rebels, and the Syrian military have slowly re-taken many of ISIS's strongholds over the last several months.
Syrian rebel source says civilians need aid and rebel factions should receive military support from the West against regime which has Iranian and Hezbollah allies.
Israel has reportedly been discreetly supporting Syrian rebel groups for years in order to protect its northern border from the war raging in Syria.
There has been confusion over which groups in the opposition are included in the ceasefire.
It was the first meeting between Kerry and Lavrov since the collapse of a second attempted ceasefire in September.