JFK files released but 'sensitive' documents blocked by Trump
Video report by ITV News Washington Correspondent Robert Moore
Donald Trump has delayed the release of hundreds of "sensitive" files about the assassination of President John F Kennedy.
The US President approved the release of 2,800 other files related to the 1963 killing but has placed the other records under a six-month review after appeals from the CIA and FBI.
What is in the newly released files?
The documents are unlikely to alter the overall narrative of the assassination and investigation, but they do shed new light on aspects of both while providing a few unusual nuggets of information, including:
Did the Cambridge News get a tip-off?
Among the newly released documents is the revelation that the UK's Cambridge News received an anonymous call about "some big news" in America 25 minutes before Kennedy was assassinated.
A memo to the director of the FBI said the anonymous phone call was made to the newspaper's senior reporter.
The document, from deputy director James Angleton, states: "The caller said only that the Cambridge News reporter should call the American Embassy in London for some big news and then hung up."
The Soviet Union's fears over Oswald
Documents from then-FBI director J Edgar Hoover reveal the Soviet Union feared they would be blamed for putting Lee Harvey Oswald up to assassinating Kennedy.
A threat had been made to kill Oswald the night before he was shot.
Hoover wanted public to believe Oswald acted alone
"There is nothing further on the Oswald case except that he is dead."
That was the memo dictated by Hoover the day Oswald was shot dead by local nightclub owner Jack Ruby.
Hoover said Oswald's killing was "inexcusable" after the FBI warned the Dallas Police Department to protect the prime suspect.
Hoover later publicly quashed talk of a conspiracy and sought "something issued so we can convince the public that Oswald is the real assassin".
Investigators pursued every possible lead
The documents approved for release show federal agents madly chasing after tips in the days after the assassination and juggling rumours and leads worldwide.
Kennedy's planned moves on Castro
The materials also cast a wide net over varied activities of the Kennedy administration, such as its covert efforts to upend Fidel Castro's government in Cuba.
In a September 14, 1962, meeting disclosed in the files, for example, a group of Kennedy's senior aides, including brother Robert, the attorney general, discussed a range of options against Castro's communist government.
The meeting was told the CIA would look into the possibility of sabotaging airplane parts that were to be shipped to Cuba from Canada.
McGeorge Bundy, JFK's national security adviser, cautioned that sensitive ideas like sabotage would have to be considered in more detail on a case-by-case basis.
Why are some files being withheld?
In a White House memo Mr Trump stated he had "no choice" but to withhold the hundreds of records as the deadline to honour a law mandating the release of the JFK files approached.
Officials say the president will impress upon federal agencies that JFK files should stay secret after the six-month review "only in the rarest cases".
Mr Trump has the power to block records on the grounds that making them public would harm intelligence or military operations, law enforcement or foreign relations.
White House officials said the FBI and CIA made the most requests within the government to withhold some information.
What is the official account of the Kennedy assassination?
Kennedy was travelling with his wife Jacqueline in an open-topped limousine through Dealey Plaza in Dallas, waving to crowds, when three shots rang out at 12.30pm.
Two bullets hit Kennedy in the head and neck. His death was announced on the same day at 1.33pm. Police officer JD Tippit also died.
Investigators found the shots came from the Texas School Book Depository.
Lee Harvey Oswald was charged with both murders, but he denied killing them.
Two days after Kennedy's murder, the 24-year-old Oswald was shot dead in the Dallas police department by a local nightclub owner, Jack Ruby, before he had the chance to give his version of events.
Why is there such intrigue around JFK's death?
An official inquiry, the Warren Commission set up by President Johnson, determined that Oswald acted alone. It also found that Ruby was not part of a bigger plot or cover-up.
However another later inquiry by the House Select Committee on Assassinations found Kennedy "was probably assassinated as a result of a conspiracy".
It determined there was a "high probability that two gunmen fired".
This fuelled myriad theories about who was ultimately behind the president's death.
Why are the files being released now and will they challenge the official version of events?
Congress ruled in 1992 that all assassination documents should be released within 25 years.
More than 30,000 records have been previously released but with redactions.
Months ago a statement from the Archives said that it assumed the records would be "tangential" to what is already known about the assassination which took place on 22 November 1963.