The fighter jet and its pilot, Capt. Lucas Gruenther, have been missing since Monday when Aviano Air Base in northern Italy lost contact with him.
The 31st Fighter Wing launched several of its F-16 Fighting Falcon aircraft Wednesday in the search for the Capt. Lucas Gruenther, the Wings' chief of flight safety, air base officials said on base's website.
Gruenther was conducting an F-16 training sortie over the Adriatic Sea when contact was lost with his aircraft.
"While not specifically designed for reconnaissance like the other aircraft already involved in the search, our F-16s have targeting pods which can be used to augment the search," said Brig. Gen Scott J. Zobrist, 31st Fighter Wing commander.
The plane's last known contact was about 10 or 15 nautical miles off the coast of Cervia.
U.S. and Italian military officials were coordinating rescue efforts.
"We'll continue to operate day and night until we can rescue the pilot or determine what happened," said Maj. Erick Saks, chief of public affairs for the 31st Fighter Wing.
Aviano Air Base doesn't have recovery aircraft of its own, Saks said, so the initial effort was mostly Italian.
Several U.S. military aircraft joined the search Tuesday, Stars and Stripes reported.
Italian news service ANSA reported the pilot signaled a "problem" but did not specify what it was before contact was lost. Saks said the U.S. and Italian air forces had not released any information regarding possible "chatter."
ANSA also reported traces of jet fuel were found but Saks said he could neither confirm nor deny the report.