The Obama administration has accused Russian forces of the airstrike on a UN aid convoy, which shattered the fragile peace agreement in Syria.
It comes as foreign ministers, including Russia’s Sergei Lavrov and the US’s John Kerry, met at the UN General Assembly to discuss how to extend the truce.
Later, at the White House, Deputy National Security Advisor Ben Rhodes said: “All of our information indicates clearly that this was an air strike. That means there only could have been two entities responsible: either the Syrian regime or the Russian government. In any event, we hold the Russian government responsible for air strikes in this space given that their commitment under the cessation of hostilities was to certainly ground air operations in places where humanitarian assistance is flowing.”
Russia denies involvement. They said that it was Syrian rebels who destroyed the convoy, from the ground, not the air.
The Russia also said that drone footage , released by the Russian Defence Ministry, shows a pick-up truck and heavy mortar weapon belonging to rebel militants who were behind the attack.
Since the attack, which destroyed 18 vehicles and killed around 20 civilians, the UN has stopped all aid convoys to Syria.
A UN spokesperson said that this attack, whoever was in fact responsible, amounted to a war crime.
But efforts to maintain the cessation of hostilities have not finished. The UN Security Council will meet on Wednesday to discuss Syria, and Kerry and Lavrov will meet again on Friday.