US President Donald Trump has said he would release all documents related to the 1963 assassination of President John F. Kennedy, except those with the names and addresses of people who are still alive.

"After strict consultation with General Kelly, the CIA and other Agencies, I will be releasing ALL #JFKFiles other than the names and addresses of any mentioned person who is still living," Mr Trump wrote in a series of tweets, referring to his chief of staff John Kelly.

Mr Trump said he would be doing so "for reasons of full disclosure, transparency, and in order to put any and all conspiracy theories to rest."

Prior to his comments, Mr Trump had yielded to pressure from the FBI and CIA to block the release of some records, which will be the subject of a further review.

Congress had ordered in 1992 that all remaining sealed files pertaining to the investigation into Kennedy's death should be fully opened to the public through the National Archives in 25 years, by 26 October 2017, except for those the president authorised for further withholding.

The massive cache of documents is being pored over by investigators, scholars and conspiracy theorists.

Some documents are to be released "on a rolling basis," with "redactions in only the rarest of circumstances," by the end of a review on 26 April 2018, the White House said in a statement this week.