The US national archives released 13,173 documents related to the murder after President Joe Biden issued an executive order authorising it, while also keeping hundreds of other sensitive records secret for up to another year.

The files are not expected to include any new bombshells or change the conclusion reached by Warren Commission led by Chief Justice Earl Warren that killer Lee Harvey Oswald, a former Marine and communist activist who had lived in the Soviet Union, acted alone.

Kennedy was shot and killed while riding in a motorcade through Dallas on 22 November at the age of 46.

Thousands of books, articles, TV shows and films have explored the idea the president's assassination was the result of an elaborate conspiracy, involving bodies such as the Central Intelligence Agency (CIA), the mafia, the Russians or even his vice-president Lyndon B Johnson.

No one has ever produced conclusive proof that Oswald - who was fatally shot by nightclub owner Jack Ruby two days after killing Kennedy - worked with anyone else, although it has had a considerable afterlife as a conspiracy theory in the 59 years since the assassinations took place.

Many of the documents released on Thursday belonged to the CIA, including several that focused on Oswald's movements and his contacts.

The US government opened a file on Oswald in December 1960, nearly three years before Kennedy's murder and after his failed defection to the Soviet Union in 1959.

A December 1963 document described how CIA officials in Mexico City "intercepted a telephone call" Oswald made in October from that city to the Soviet Embassy there "using his own name" and speaking "broken Russian."

Oswald was hoping to travel through Cuba on his way to Russia and was seeking a visa, documents show.

There were initial concerns that Ruby, Oswald's killer, might have had some connection to Oswald.

But a newly released September 1964 memo to the presidential commission investigating the assassination said "the Central Intelligence Agency has no indication that Ruby and Lee Harvey Oswald ever knew each other, were associated, or might have been connected in any manner".

It has taken many years for the files to see the light of day. Congress ordered in 1992 that all remaining sealed files relating to the investigation into Kennedy's death should be fully opened to the public by 2017, except for those the president authorised for further withholding.

In 2017, Donald Trump released a cache of records, but decided to release the remaining documents on a rolling basis. The remaining JFK files were originally supposed to have been released in October 2021.

Biden postponed that planned release, citing delays caused by the COVID-19 pandemic, and announced they would be instead disclosed in two batches: one in December 2021, and another by December 15, 2022, after undergoing an intensive one-year review.

With Thursday's release, 95% of the documents in the CIA's JFK assassination records collection will have been released in their entirety.