Last year, the Pentagon’s All-domain Anomaly Resolution Office (AARO) directly addressed some of the more far-reaching public claims of former military personnel and other U.S. officials about government contact with aliens. The 60-page study explained in detail the history of government research into UAP, and it specifically denied charges that the Pentagon has known for years about UFOs of extraterrestrial origin and has engaged in a highly secretive program to reverse-engineer their spaceships.

Critics say the report hid the truth. Mr. Elizondo testified that the government does operate secret UAP crash retrieval programs, but lawmakers of both parties said their efforts to learn more have been largely unsuccessful.