The Russian Defence Ministry said on Wednesday that a U.S. Predator drone was in the area where a U.N. aid convoy was partially destroyed in Syria on Monday and had appeared on the scene minutes before the incident. The claims were strongly denied by the Pentagon.Repeating denials of Russian involvement in the episode, Igor Konashenkov, a spokesman for the ministry, said Western allegations that Moscow was responsible were an attempt to distract attention from the U.S.-led coalition's bombing of Syrian soldiers near Deir al-Zor airport on Saturday.

However, the Pentagon strongly denied Russia's claim only hours after the Russian ministry's statement. "None of our aircraft -- manned or unmanned, US or coalition -- were anywhere in the vicinity of Aleppo when the strike against the humanitarian convoy occurred," Pentagon spokesman Navy Captain Jeff Davis said.

Meanwhile, U.S. Secretary of State John Kerry said that all aircraft over key humanitarian routes should be grounded in order to restore the flow of "desperately" needed aid deliveries.

Speaking to the U.N. Security Council, Kerry said the step "could restore credibility" to end the civil war in Syria, adding that it would "give a chance for humanitarian assistance to flow unimpeded."

Kerry also said that grounding the aircraft could prevent the Syrian regime from attacking civilians in the guise of fighting the al-Nusra front.

On Monday, a U.S./Russia-brokered seven-day cessation of hostilities to allow humanitarian aid into the country came to an end, but with little progress in improving conditions on the ground.

Over the weekend, U.S.-led anti-Daesh aircraft inadvertently hit a Syrian military camp and killed 62 Syrian soldiers, further fraying relations between Washington and Moscow over Syria.