The U.N. Security Council met for urgent talks on Sunday as Syrian and Russian warplanes pounded rebel-held east Aleppo in the worst surge of bombing to hit the devastated city in years.
Britain, France and the United States called the emergency meeting to turn up pressure on Russia and press demands that it rein in its ally Syria to halt the intense bombing campaign on Aleppo.
"War crimes are being committed here in Aleppo," French Ambassador Francois Delattre told reporters, adding: "They must not be unpunished and impunity is simply not an option in Syria."