"It's a lot of stuff, and you'll make your own determination," Trump told reporters on Monday, saying 80,000 pages would be released.
Trump signed an order shortly after taking office in January related to the release, prompting the US Federal Bureau of Investigation to find thousands of new documents related to the Kennedy assassination in Dallas.
In the scramble to comply with Trump's order, the US Justice Department ordered some of its lawyers who handle sensitive national-security matters to urgently review records from the assassination, according to an email seen by Reuters.
A White House official said the documents would be released on Tuesday through the National Archives.
Kennedy's murder has been attributed to a sole gunman, Lee Harvey Oswald.
The Justice Department and other federal government bodies reaffirmed that conclusion in the intervening decades.
But polls show many Americans believe his death was a result of a conspiracy.
Experts doubt the new trove of information will change the underlying facts of the case, that Oswald opened fire at Kennedy from a window at a school book deposit warehouse as the presidential motorcade passed by Dealey Plaza in Dallas.
"People expecting big things are almost certain to be disappointed," said Larry Sabato, the director of the Center for Politics at the University of Virginia, who authored a book about the assassination.
He said some of the pages could simply be the release of previously published material that had a few words redacted.
Trump has also promised to release documents on the assassinations of civil rights leader Martin Luther King Jr and Senator Robert Kennedy, both of whom were killed in 1968.
Trump has allowed more time to come up with a plan for those releases.
Trump's secretary of Health and Human Services, Robert F Kennedy Jr, the son of Robert Kennedy and nephew of John F Kennedy, has said he believes the Central Intelligence Agency was involved in his uncle's death, an allegation the agency has described as baseless.
Kennedy Jr has also said he believes his father was killed by multiple gunmen, an assertion that contradicted official accounts.
One revelation the documents could contain is that the CIA was more aware of Oswald than it has previously disclosed.
Questions have remained about what the CIA knew about Oswald's visits to Mexico City six weeks before the assassination. During that trip, Oswald visited the Soviet embassy.
"People have been waiting for decades for this," Trump said.
"It's going to be very interesting."
