UN air drops aid to besieged Syrian city Deir al-Zor

The UN has airdropped aid to the besieged Syrian city of Deir al-Zor, though it isn't yet clear if the operation was successful.

Syrian Red Crescent staff survey the delivery of humanitarian aid at a warehouse in Kafr Batna, in the rebel-held Eastern Ghouta area, southern Syria, on the outskirts of the capital Damascus on February 23, 2016. Source: AAP

The United Nations has carried out its first airdrop of humanitarian aid to the Syrian city of Deir al-Zor, says UN aid chief Stephen O'Brien, delivering 21 tons of relief to civilians besieged by Islamic State militants.

"Earlier this morning a WFP (World Food Programme) plane dropped the first cargo of 21 (metric) tons of items into Deir al-Zor," O'Brien told the UN Security Council on Wednesday.

"We have received initial reports ... that pallets have landed in the target area."

However, UN spokesman Stephane Dujarric later told reporters the WFP was still trying to get information on where the aid ended up, suggesting it may not have all reached the target area.

"As you know, airdrops can be very challenging," he said.

"The pallets were dropped. They're (the WFP) trying to reach local partners to ensure that the aid was received."

"There may have been some difficulties in terms of the pallets," he added.

Dujarric said the WFP was trying to reach some 200,000 people in Deir al-Zor and there would likely be further airdrops in the coming days.