(Reuters) – President Donald Trump on Thursday signed an order related to the declassification of files on the assassinations of former president John F. Kennedy, Robert Kennedy, and Martin Luther King Jr., an aide to Trump said.

“Give that to RFK Jr.,” Trump said about the pen he used to sign the order declassifying information about the JFK, RFK and MLK assassinations. “All will be revealed.”

Trump had promised on the campaign trail to release classified intelligence and law enforcement files on the 1963 assassination of JFK, America’s 35th president.

He had made a similar promise during his 2017 to 2021 term, and he did in fact release some documents related to JFK’s 1963 slaying. But he ultimately bowed to pressure from the Central Intelligence Agency and Federal Bureau of Investigation, and kept a significant chunk of documents under wraps, citing national security concerns.

The JFK assassination, in particular, is a source of enduring fascination in the United States. The murder has been attributed to a sole gunman, Lee Harvey Oswald, and the Justice Department and other federal government bodies have reaffirmed that conclusion in the intervening decades. But polls show many Americans believe his death was a result of a wider conspiracy.