Donald Trump said “everything will be revealed” as he signed an executive order to declassify files on the assassination of former US president John F Kennedy.

The US president had promised on the campaign trail to release classified intelligence and law enforcement files on the 1963 assassination of JFK, as America’s 35th president is widely known.

The order will also declassify federal records relating to the assassinations of Senator Robert F Kennedy, and Martin Luther King Jnr.

Speaking to reporters on Thursday, Mr Trump said: “That’s a big one, huh?

“A lot of people are waiting for this for a long ... for years, for decades.”

He added: “Everything will be revealed.”