RNA - The meeting was likely to be held at 10 am (1400 GMT) on Sunday, the diplomats said, AFP reported on Sunday.
UN Secretary General Ban Ki-moon earlier said he was appalled by the "chilling" upsurge in fighting in Aleppo and warned that the use of advanced weaponry in the battleground city could amount to war crimes.
He warned that "the apparent systematic use of these types of indiscriminate weapons in densely populated areas may amount to war crimes," a statement from his spokesman said.
A weeklong ceasefire agreed between the United States and Russia ended on Monday and efforts to revive the truce failed.
Last Saturday, US-led coalition jets bombed Syrian government forces’ positions near the eastern city of Deir ez-Zor, killing 62 troops and "paving the way" for Daesh terrorists.
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