Donald Trump has ordered the release of 2,800 files relating to the assassination of John F Kennedy, but agreed to withhold hundreds of documents the US intelligence community still deems sensitive more than 50 years after the incident.

The documents were published on the National Archives' website late on Thursday, leaving analysts to pore over hundreds of thousands of individual pages, some of them hand-written, that encompass areas including CIA assassination plots and Martin Luther King Jr's political leanings.

Mr Trump had said he wanted to release all government material relating to the 1963 shooting of the 35th president, but had been persuaded to provide a six-month exception for some material. Most of the files not being made public come from the CIA and FBI, and the fact some are being held onto will likely fuel further conspiracy theories, rather than make them go away.

Asked if Mr Trump was angry that he had been unable to fulfil his undertaking to release all the material - some had suggested the delay was a deliberate snub from the intelligence community after repeated clashes between the President and senior officials in various agencies - a senior government official, speaking on background, told reporters: “The President wants to ensure full transparency and he thinks the agencies can do a better job at reducing any conflict within the redaction and get this information out as quickly as possible.”

The assassination of JFK – in pictures Show all 8 1 /8 The assassination of JFK – in pictures The assassination of JFK – in pictures President John F. Kennedy and his wife Jacqueline Kennedy ride with secret agents in an open car motorcade shortly before the assassination, 22 November 1963 Getty The assassination of JFK – in pictures President John F. Kennedy and his wife Jacqueline Kennedy prior to his assassination Keystone/Getty The assassination of JFK – in pictures Kennedy is struck by an assassin's bullet as he travels through Dallas in a motorcade In the car next to him is his wife Jacqueline and in the front seat is Texas governor John Connally Three Lions/Hulton Archive/Getty The assassination of JFK – in pictures The view from the sixth floor window of the Texas School Book Depository in Dallas, from which Lee Harvey Oswald is thought to have assassinated Kennedy. This photograph was taken approximately one hour after the assassination Hulton Archive/Getty The assassination of JFK – in pictures Lee Harvey Oswald during a press conference after his arrest in Dallas. Lee Harvey Oswald was killed by Jack Ruby on 24 November on the eve of Kennedy's burial AFP/Getty The assassination of JFK – in pictures Lyndon B. Johnson takes the oath of office as President of the United States on the day of Kennedy's assassination. Jackie Kennedy is stood next to Johnson Getty The assassination of JFK – in pictures Kennedy's funeral procession goes into Arlington Cemetery in Washington Newsmakers/Getty The assassination of JFK – in pictures Kennedy's casket sat in the East Room of the White House Newsmakers/Getty

Shortly after the government officials spoke, the White House issued a memorandum from the President that said the “American public expects - and deserves - its government to provide as much access as possible to the President John F Kennedy Assassination Records so that the people may finally be fully informed about all aspects of this pivotal event”.

The memo said Mr Trump was ordering “that the veil finally be lifted”.

It added: “At the same time, executive departments and agencies have proposed to me that certain information should continue to be redacted because of national security, law enforcement, and foreign affairs concerns. I have no choice - today - but to accept those redactions rather than allow potentially irreversible harm to our nation's security.”

The assassination of Kennedy, as he toured Dallas with the First Lady, Texas Governor John Connally and his wife, Nellie, remains one of the most iconic and controversial moments in modern US history. A year after the killing, the Warren Commission, established by Kennedy’s successor, Lyndon Johnson, concluded the most powerful man in the world had been killed by Lee Harvey Oswald, a 24-year-old former marine, using a bolt-action rifle he bought by mail order.

Contrary to intense speculation and theorising, the commission’s exhaustive investigation concluded the troubled young man, who had emigrated to Russia for two years, had acted alone. It found no evidence to support suggestions that Russia, Cuba, the mafia, or any one of countless other countries, organisations or individuals who may have had a gripe with the US president, were involved.

Yet 54 years on, that idea is no more palatable to the American public than it was at the time of the assassination. A recent survey commissioned by the website FiveThirtyEight found that two-thirds of the public rejected the official finding and believed there was more than one gunman involved.

Experts said the trove of new documents were unlikely to provide any stunning new details about the killing. Yet they said making public the material - or at least most of it - would help dispel suspicions of a conspiracy. The chaotic, last-minute nature in which the release was held up will be fuel to some who believe the intelligence communities do not want to cooperate.

“As long as the government is withholding documents like these, it’s going to fuel suspicion that there is a smoking gun out there about the Kennedy assassination,” Patrick Maney, a presidential historian at Boston College, told the Associated Press.

The collection includes more than 3,100 documents, comprising hundreds of thousands of pages, that have never been seen by the public. About 30,000 documents were released previously, albeit with redactions.

Experts said intelligence agencies pushed Mr Trump to keep some of the remaining materials secret.