Gen. Dan McNeill commented about NATO forces being "under-resourced" as he turned over command of the International Security Assistance Force to another American, Gen. David McKiernan, the BBC reported.
NATO has 53,000 troops from 40 countries deployed in Afghanistan.
"This is an under-resourced war and it needs more maneuver units, it needs more flying machines, it needs more intelligence, surveillance and recognizance apparatus," McNeill said.
Meanwhile, a U.S.-led coalition operation Tuesday killed several militants in southern Afghanistan, a coalition spokesman said.
The raids, which officials said targeted "anti-government militant operations," took place in Helmand, province, CNN reported.
The soldiers used small-arms fire, mortars and air strikes against the militants, the coalition said.