President Trump said on Thursday that he had directed his administration to begin releasing files related to aliens, extraterrestrial life and unidentified flying objects, only hours after attacking former President Barack Obama for saying that aliens were real.

It was the latest effort by Mr. Trump, ever the television showman, to stir anticipation for the release of secret government documents, even as he has continued to lash out at reporters over the release of the Jeffrey Epstein files and his connections to the disgraced financier. The release of the Epstein files has dragged on for nearly a year and Mr. Trump did not set a timeline for files on aliens.