Moscow, meanwhile, says the United States failed to separate "moderate" anti-Assad rebels from jihadists linked to Al-Qaeda
Ahmed Salama Mabrouk, an Egyptian also known by his nom de guerre Abu Faraj, had been killed in Idlib province in northwestern Syria
A hospital source in Hasakeh city told AFP there were more than 20 dead and dozens wounded
Diplomats were holding negotiations on the text on Monday and a vote at the council could take place this week
A medical source in rebel-held Aleppo said hospitals were struggling to deal with a huge number of casualties
Hospitals and rescuers have documented the deaths of 43 people so far
Nearly two million civilians were left without water in Aleppo due to regime bombardment and rebel forces
Announcement came just minutes after the United States and Russia convened a last-ditch meeting in New York to save their Syria ceasefire plan
Use of chlorine as a weapon is banned under the Chemical Weapons Convention, which Syria joined in 2013
At least 18 trucks in a 31-vehicle convoy were destroyed late Monday as they delivered humanitarian aid to civilians in the Aleppo region
Russian and Syrian planes yesterday, bombed an aid convoy that was en route to Aleppo to deliver food to 78,000 civilians
Syrian Observatory for Human Rights said 12 Red Crescent volunteers and drivers had died in the strike
The US failed to help separate terrorists from the so-called moderate opposition, said Russia
The Russian president insisted Moscow is adhering to its part of the agreement
A barrage of rocket fire and shelling could be heard coming from the Jobar district, a rebel-held eastern suburb of Damascus
More than 86,000 civilians were among the 301,781 people killed, the Syrian Observatory for Human Rights said
Russia is to pressure Bashar al-Assad to obey the truce, while US will urge the rebel groups it supports to refrain from attacks
More than 290,000 people have been killed and over half the population displaced since the conflict began
At least 62 people, including 13 women and 13 children, were killed in Saturday's bombardment of Idlib city
Agreement was announced by the US Secretary of State, John Kerry, and his Russian counterpart Sergei Lavrov