The UN and Russia are discussing about stopping hostilities in the divied Syrian city of Aleppo in efforts to help the two million people trapped in the city.
While Russian officials have announced a daily three hour pause, the UN wants a weekly three hour break.
The discussions are holding at a time when there are claims that suspected chlorine gas was dropped alongside barrel bombs on a neighbourhood in Aleppo on Wednesday.
It is believed four people died, while many others suffered breathing difficulties after the incident.
“It’s really not for me to assess who did it and whether it actually took place, although there’s a lot of evidence that it actually did take place. We have a special UN and other organisation addressing that. But if it did take place, it is a war crime,” Staffan de Mistura, UN Special Envoy to Syria said.
The upsurge of intense fighting around Aleppo in recent weeks has killed scores of Syrians, displaced thousands – and cut water and power.
Advances by warring sides, which have led to a siege of rebel-held neighbourhoods and the severing of a major route into government areas of control, have choked off supplies.
There are fears that the entire civilian population has been encircled.