Russia's Defence Ministry has maintained that its planes were not in the area when the UN aid convoy was hit.

Instead, it says that a US Predator drone arrived in the area minutes before the convoy caught fire, and left about 30 minutes later.

The ministry's spokesperson said that such drones were armed with air-to-ground missiles. He also said Russia was not drawing any conclusions about the drone's presence, but added that accusations towards Moscow were an attempt to distract attention from the deadly US-led bombing of Syrian soldiers on Saturday.

"Our Western colleagues are doing everything to blur the background information of the tragedy in the city of Deir al-Zor, and are intentionally diverting the focus and attention of the global community from the escalating offensives of Jabhat al-Nusra militants in the city of Aleppo," said Major-General Igor Konashenkov, spokesman of Russian Defense Ministry.

"And thus hide the failure of the United States of America in distinguishing between the moderate opposition and terrorists in Syria."