US Secretary of State John Kerry is threatening to end US engagement with Russia on Syria unless Russia takes "immediate steps" to end the assault on Aleppo.
Kerry has told Russian Foreign Minister Sergei Lavrov that the US holds Russia responsible for the situation in Aleppo amid attacks on civilians by the Syrian regime.
"He informed the foreign minister that the United States is making preparations to suspend US-Russia bilateral engagement on Syria ... unless Russia takes immediate steps to end the assault on Aleppo and restore the cessation of hostilities," spokesman John Kirby says.
