US President-elect Donald Trump has expressed his intention to release classified government documents, including on the 1963 assassination of US President John F. Kennedy.

Trump made the comments while speaking to supporters at a rally on Sunday, ahead of his presidential inauguration.

He said he will also make public undisclosed records of great public interest, such as about the assassinations of JFK's younger brother US Attorney General Robert Kennedy and civil rights leader Martin Luther King Jr.

Trump said that in the coming days his administration will "reverse" the over-classification of government documents as the first step toward restoring government transparency and accountability.