U.S. and Japanese officials say that speculations that foreign adversaries are after the wreckage of a downed F-35A stealth fighter in Asia are so far unfounded.

The Japanese F-35 stealth fighter jet disappeared from radar over the Pacific Ocean earlier this month during a night training flight.

Some wreckage of the aircraft was found last week. Maj. Akinori Hosomi, the pilot, is missing and the U.S. is assisting in the search.

MISSING JAPANESE F-35 POSES MAJOR SECURITY HEADACHE FOR US IF IT FALLS INTO RUSSIAN OR CHINESE HANDS

The missing jet prompted security concerns and fears that China or Russia could discover the wreckage.

“If one of Japan’s F-35s is sitting at the bottom of the Pacific, we are probably about to see one of the biggest underwater espionage and counter-espionage ops since the Cold War. If it was operating without its radar reflectors pinpointing where it went in may be an issue,” tweeted Tyler Rogoway, editor of The War Zone.

“It could present problems depending on what is recovered, when it is recovered and, above all, in which conditions, after impacting the surface of the water,” Rome-based aviation expert, pilot, and former Italian Air Force officer David Cenciotti told Fox News. “The F-35 is a system of systems and its low observability/stealthiness is a system itself.”

WRECKAGE OF MISSING JAPAN'S F-35 FIGHTER JET FOUND, PILOT REMAINS MISSING

Both the U.S. and Japanese officials, however, dismissed the speculations as unfounded, saying that the U.S. military hasn’t seen evidence of any hostile powers trying to get hold onto the wreckage.

“There has been a lot of wild speculation in the media about other countries racing to find the wreckage,” a U.S. military official told the Stars and Stripes. “To date, we’re not seeing it, but we continue to monitor.”

“There has been a lot of wild speculation in the media about other countries racing to find the wreckage. To date, we’re not seeing it, but we continue to monitor.” — A U.S. military official

The official echoed Japan’s Defense Minister Takeshi Iwaya remarks to reporters last week, saying there’s no evidence that other governments are seeking for the lost plane.

CLICK HERE FOR THE FOX NEWS APP

“We have been watching the activities of foreign aircraft and vessels in the area surrounding our country 24 hours and 365 days, but we have not confirmed any unusual cases,” he said, according to the outlet.

Fox News' James Rogers and the Associated Press contributed contributed to this report.