A NATO official said on Friday that the US submitted the appeal to do so in December.

The US is currently leading a anti-"Islamic State" ("IS") coalition of some 60 countries in Syria, including all 28 NATO members and regional members such as Egypt and Saudi Arabia.

"We can confirm there has been a request for concrete support from NATO to the anti-[IS] effort in the form of NATO AWACS surveillance planes," the official said on Friday.

The unit of AWACS - Airborne Early Warning and Control System surveillance planes - comprises more than 20 planes which can locate and identify other aircraft more than 400 kilometers (643 miles) away.

The fleet could act as flying command posts, communicating with other aircraft, helping to warn of threats and coordinate coalition airstrikes against IS.

"Any decision would be in line with the Wales summit declaration which indicates NATO's readiness to support the bilateral efforts of allies," the NATO official said, referring to a 2014 meeting of alliance leaders.

Reluctance to join conflict

NATO has so far refused to participate in the conflict in Syria, partly due to concerns from alliance members such as Germany, who fear that NATO's involvement could complicate peace negotiations.

The fleet of 16 AWACS - which is currently based in Geilenkirchen, near the western German city of Aachen - is a group of specially adapted Boeing 707s.

The aircrafts are usually flown by a 16-strong crew of international military personnel, including computer and radar specialists, one third of which is usually made up of German troops.

Most recently, NATO deployed some of its AWACS to Turkey, following a request by the government in Ankara, over fears of the growing conflict in the region and the presence of Russian planes in neighboring Syria.

ksb/kms (AFP, dpa)