MOSCOW Deputy Russian Foreign Minister Sergei Ryabkov rejected a proposal by U.S. Secretary of State John Kerry for Russia and Syria to halt flying over Syrian battle zones as unworkable, the RIA news agency reported on Thursday.
Kerry made his proposal at the United Nations Security Council on Wednesday, calling it a last chance to salvage a collapsing ceasefire and find a way "out of the carnage".
Russia and the Syrian government spurned his plea with warplanes mounting the heaviest air strikes in months against rebel-held districts of the city of Aleppo overnight, burying any hope for the revival of a doomed ceasefire.
RIA cited Ryabkov as explaining why Moscow had rejected Kerry's idea.
"This (Kerry's) plan won't work," it cited him as saying.
"At least not until such time as not just the United States but also other players in this process ... have ensured that those groups who remain convinced that war is the only way of resolving the problem and that violence is the only way of toppling (Syrian President Bashar al-) Assad embrace the non-use of force."
Ryabkov said Russian Foreign Minister Sergei Lavrov and Kerry would continue discussing Syria at the U.N. on Thursday.
(Reporting by Dmitry Solovyov; Editing by Andrew Osborn)