Russia’s UN ambassador, Vassily Nebenzia, told the council in New York his country had presented amendments.
Speaking at an emergency meeting of the council, he called for “feasible” rather than “populist” action.
Calls for a truce have grown louder as civilians in the besieged rebel enclave of the Eastern Ghouta come under more intensive bombardment.
The draft, put forward by Kuwait and Sweden, calls for a 30-day nationwide truce to go into effect 72 hours after the resolution is passed.
Medical evacuations and aid deliveries would start 48 hours after that. The draft says 5.6 million people in 1,244 communities across the country are in acute need.
But any ceasefire would not apply to the Islamic State group, al-Qaeda and the al-Nusra Front.
Russian Foreign Minister Sergei Lavrov has made clear that Hayat Tahrir al-Sham, an al-Qaeda-linked alliance that has a presence in the Eastern Ghouta, must not be included.
Mr Lavrov said he also wanted to exclude rebel groups in the enclave who are “co-operating” with Hayat Tahrir al-Sham and shelling nearby government-held areas.
The draft also calls for all parties to avoid establishing military positions in civilian areas, including schools and hospitals. Sieges of populated areas should be lifted.
The United States, the UK and France are calling for the resolution to be approved without delay.
Russia’s UN ambassador, whose country is one of the five powers that can veto a resolution, stressed the need for something that would actually work.
“The ceasefire carries great significance in principle and not merely for the delivery of humanitarian assistance,” he said.
“The challenge is how to achieve this. And here what we need is not symbolism, not decisions for the sake of decisions, but rather measures that are undertaken that are commensurate with conditions on the ground.”
Russia is a key backer of Syria’s President Basher al-Assad in the civil war and the suspicion among Western powers is that Moscow is stalling to allow their ally to deal a final blow to rebel forces.
Deputy US ambassador to the UN Kelley Currie accused Russia of standing in the way of “any meaningful effort” to halt the fighting in the Eastern Ghouta.
For the fifth day running, Syrian government forces carried out a wave of air and artillery strikes.
The number killed since Sunday has risen to at least 403, the Syrian Observatory for Human Rights monitoring group says, as 46 more died on Thursday. (Courtesy BBC)