Moscow reacted furiously to "unsubstantiated" accusations from the United States that Syrian or Russian planes were responsible for bombing an aid convoy in Syria’s Aleppo.

At least 18 trucks in a 31-vehicle convoy were destroyed late Monday as they delivered humanitarian assistance to desperate civilians in Orum al-Kubra in the Aleppo region, according to the UN.

Washington said the alleged air strike could only have been carried out by Syrian President Bashar al-Assad’s regime or his Russian allies and that Moscow must take responsibility either way.

The Russian foreign ministry said it was watching "with indignation and anger" at attempts by "protectors of terrorists and bandits" to blame Russia or Syria for the attack.

The "unsubstantiated, hasty accusations" seemed designed to "distract attention from the strange ‘error’ of coalition pilots," said the statement on Monday, referring to the US-led coalition which struck a Syrian army position at the weekend killing dozens of soldiers.

The Russian military, which is investigating the incident, said that footage from activists at the scene showed damage to the vehicles that did not appear to come from an air strike or other munitions.

Instead, the fire that tore through the convoy happened "strangely at the same time insurgents were carrying out a large-scale attack on Aleppo," defence ministry spokesman Igor Konashenkov said in a statement.

Konashenkov said Russian drones had followed the convoy until it successfully delivered its load, but had stopped surveillance after that.

"All information on the convoy’s location (after that) was known only to the rebels controlling this area," he said.

Syria’s army has also denied bombing the aid trucks, with a military source telling state media that there was "no truth" to media reports that the Syrian army was responsible.

The deadly attack occurred several hours after Syria’s military declared an end to a week-long truce brokered by the Moscow and Washington earlier this month in an attempt to end the five-year war.

The United Nations has since suspended all humanitarian aid convoys.

Kremlin spokesman Dmitry Peskov said hope for a renewal of the ceasefire was "for now, very weak", stressing that a truce could only be resumed if "terrorists" halted their fire.

"The conditions are very simple. The shooting needs to stop and the terrorists need to stop attacking Syrian troops," he said.