Russia had agreed to sit down with the United Nations
Fierce fighting is reported to have resumed around the Syrian city of Aleppo, after an unsuccessful ceasefire earlier.
The announcement came hours after a three-hour daily ceasefire reportedly failed to take effect.
It was announced by Russia to allow humanitarian and aid deliveries in the city.
Russia had agreed to sit down with the United Nations to try to agree a "workable humanitarian pause" in fighting in the besieged city.
Violations of the Russian proposal, which had been due to come into force on Thursday morning, were reported on both sides.
Moscow's call for the daily three-hour halt in fighting was greeted with scepticism by rebel forces, while the United Nations warned that the pause was not long enough to ease the humanitarian crisis faced by hundreds of thousands of civilians in the city.
UN humanitarian adviser Jan Egeland said that a 48-hour pause each week was required to ensure the safe delivery of aid, adding that he was "hopeful" Russia would consider this proposal.
"What is the new and positive thing today is that the Russian Federation said they would like to sit down with us and the other co-chair (the United States) to discuss how the UN proposal could be implemented," he said.
"We are hopeful that will lead to something."
Aleppo, Syria's most populous city before the war, is the subject of a bitter fight between various rebel forces and Russian-backed government forces.
Last week, rebels broke a month-long government siege in the city's east, where an estimated 250,000 people are believed to be trapped.
Fierce fighting continues, however, meaning a safe corridor for civilians and aid has not yet been established.
On Thursday, reports claimed at least four people have been killed in a suspected chlorine gas attack in the east of the city.
The gas is believed to have been dropped alongside barrel bombs on the Zubdiya neighbourhood, which is in the rebel-held part of Aleppo.
UN special envoy for Syria, Staffan de Mistura, has said there is a "lot of evidence" a gas attack occurred, adding that if it is confirmed it would constitute a war crime.
Hamza Khatib, manager of Al Quds hospital, told Reuters that he had recorded four deaths and 55 injuries.
While a Syrian doctor managing an MSF-supported hospital in east Aleppo says people are scared to go to hospitals.
"We used to provide lots of services at this hospital - surgery, paediatrics, intensive care, internal medicine. But the bombings in east Aleppo over the past month forced us to focus on the increase of war-wounded patients, which became almost 80% of our work in recent weeks," Dr Hussein says.
"Before the siege, the hospitals used to see between 8,000 and 10,000 patients a month; this was halved by the beginning of July. Not only that, but also most of the patients then were war wounded, with a number of internal and paediatrics emergencies."
"One main problem we see in the hospitals is that intensive care units (ICU) are overwhelmed. Some patients are forced to stay in the operating theatre because there is no space in the ICU."
"Ventilators and oxygen purifiers are often broken because of overload. The other day two patients died because the oxygen purifier couldn’t provide proper oxygen."
he says the hospital has been damaged three times by bombings. The most severe incident was mid-July, when the hospital was forced to close for around 10 days.
Then on August 3rd, and again on August 6th, bombing around the hospital again damaged the facility.
"The hospital is running at the moment but is able to care only for the most urgent cases," Dr Hussein adds.
"People are scared to go to hospitals. They see them as potential targets. They only come to us now if it is an absolute emergency."