WASHINGTON (AFP) - A US Marine who fell into the sea after his aircraft lost power has become the first American to be killed in the ongoing air campaign against Islamic State militants.

Corporal Jordan Spears, 21, bailed out of a V-22 Osprey tilt-rotor aircraft that ran into trouble as it was taking off from the USS Makin Island on Wednesday, Oct 1, 2014.

It was his first deployment.

The US Marine Corps on Friday sent out a statement saying that search-and-rescue operations were unsuccessful and the serviceman was presumed dead. No body has been found.

The Osprey can take off like a helicopter and then - with its engines tilted down - fly like a plane. The aircraft Spears was in later landed safely.

The USS Makin Island is an amphibious assault ship supporting the US-led air campaign against the Islamic State group in Iraq and Syria.