In reality there is no doubt the UN Secretariat, Western governments, and the Idlib based Al-Qaeda command of the Jihadis in eastern Aleppo, have been coordinating their moves with each throughout the day.
Recent events on the ground in Aleppo have however rendered this all meaningless. The statement the Western governments published a few hours ago is in fact one of the most preposterous documents anyone has published over the course of the whole Syrian war.