Tim Burchett said a more than two-hour high-level Pentagon meeting this week reinforced his claim that officials are blocking fuller UFO disclosure.
The Tennessee Republican said unelected defense bureaucrats are stonewalling Congress, even claiming the president is on a "need-to-know basis" on some UAP matters.
Burchett also said pilots and service members who reported unidentified objects faced eight-hour debriefings, psych evaluations and possible removal from flight duty, discouraging witnesses from preserving footage.
The remarks come after the administration released a fourth batch of declassified UAP records this month, including military infrared videos and details of a 2015 incident near a nuclear weapons assembly facility.
That release follows Trump's February order directing agencies to begin identifying and disclosing files on UAPs, UFOs and extraterrestrial life.