US President Donald Trump has released documents related to the 1963 assassination of former President John F. Kennedy, as part of his campaign promise to provide greater transparency regarding the shocking event in Texas.

A first batch of electronic copies of the documents has been posted on the National Archives website, with more than 80,000 expected to be made public after Justice Department lawyers spent hours scrutinizing them. The digital documents include files of memos, one of which is labeled "Secret." This is a typed account, including handwritten notes, of a 1964 interview with a Warren Commission researcher in which he questioned CIA employee Lee Wegreen about inconsistencies in materials provided to the commission by the State Department and the CIA regarding Soviet-American marriages.

* Conspiracy theories

The documents also included references to various conspiracy theories suggesting that Lee Harvey Oswald, Kennedy's assassin, left the Soviet Union in 1962 intent on assassinating the popular young president.

Other documents downplayed Oswald's connection to the Soviet Union. A November 1991 document cited a report by an American university professor named E. B. Smith, who reported that he spoke in Moscow about Oswald with Soviet intelligence official "Slava" Nikonov, who said he reviewed five voluminous files on the assassin to determine whether he was a KGB agent.

"Nikonov is now confident that Oswald was never an agent under the control of the Soviet intelligence," Smith added.

* Fidel Castro

The 1963 U.S. Department of Defense documents covered the Cold War in the early 1960s and U.S. intervention in Latin America in an attempt to thwart Cuban leader Fidel Castro's support for communist forces in other countries. The documents indicate that Castro would not go so far as to provoke a war with the United States or escalate to the point of "serious and immediate danger to the Castro regime." The documents stated, "It appears likely that Castro will intensify his support for subversive forces in Latin America."

A document published in January 1962 reveals details of a top-secret project called "Operation Nemes," or simply "The Cuban Project," a CIA-led campaign of covert operations and sabotage against Cuba, approved by Kennedy in 1961, with the aim of overthrowing the Castro regime.

* "Maximum transparency"

Shortly after taking office in January, Trump signed an order releasing documents, which led the FBI to find thousands of new documents related to the Kennedy assassination in Dallas.

Amid efforts to comply with Trump's order, an email seen by Reuters late Monday showed that the Justice Department ordered some of its lawyers who handle sensitive national security cases to urgently review assassination records.

“President Trump is ushering in a new era of extreme transparency,” Director of National Intelligence Tulsi Gabbard said in a post on Twitter.

* Experts are skeptical

Kennedy's assassination was attributed to a single gunman, Oswald. The Department of Justice and other federal government agencies confirmed this conclusion in the decades that followed. But polls show that many Americans still believe his death was the result of a conspiracy.

Experts doubted that this new information would change the basic facts of the case: Lee Harvey Oswald shot Kennedy from the window of a school book warehouse as the president's motorcade passed through Dealey Square in Dallas.

"Those expecting major events will almost certainly be disappointed," said Larry Sabato, director of the Center for Politics at the University of Virginia and author of a book about the assassination. He added that some pages may simply be previously published material with some words redacted.

* CIA involvement?

Trump also promised to release documents related to the assassinations of civil rights leader Martin Luther King Jr. and Senator Robert Kennedy, who were killed in 1968. He gave Trump more time to develop a plan for releasing these documents.

Trump's Health and Human Services Secretary, Robert Kennedy Jr., son of Robert Kennedy and nephew of John F. Kennedy, said he believed the CIA was involved in his uncle's death, a claim the agency described as baseless. Kennedy Jr. also said he believed his father was killed by multiple gunmen, a claim that contradicts official accounts.

Among the things the documents may reveal is that the CIA knew more about Oswald than previously disclosed. Questions remain about what the agency knew about Oswald's visits to Mexico City six weeks before the assassination. During that trip, Oswald visited the Soviet embassy. Trump said, "People have been waiting for this for decades. It's going to be very interesting."