Staff sergeant Halex Hale, 24, went missing from his base in Aviano, northeastern Italy, on July 2nd.
He lived close to the Aviano Air Base, where he had been stationed since February 2015. He was last seen at a barbecue in Sacile, about 15km from the base, and was supposed to go from there to another friend's home nearby, but never arrived.
Italian police spent three days searching for the airman, from Middletown, Indiana, but called the search off on Saturday night, a U.S Air Force spokesman told The Associated Press.
“They found no evidence of any kind, physical or otherwise,” Captain Michael Hertzog II, told AP.
In a statement on its Facebook page on Sunday, Aviano Air Base said: "It is only the grid search around Halex's last known location that has been put on hold by Italian police.
"This does not mean we've given up, just that other options are being focused on more heavily," the statement added.
"We still believe we will find Halex, and there are hundreds of us here pulling for his safe return. We will continue to provide updates as we receive them. Please keep Halex and especially his family in your thoughts and prayers!"
The search focussed on an area close to Livenza river, Italian media reported. The U.S Air Force reportedly declined to speculate on the airman's disappearance.