Donald Trump says he will pardon a 'very important' person on Tuesday

President Donald Trump said on Monday he would pardon a "very, very important" person on Tuesday, but added it would not be leaker Edward Snowden or former national security adviser Michael Flynn.

"Doing a pardon tomorrow on someone who is very, very important," Trump told reporters on Air Force One. He declined to offer further details except to say it was not Flynn or Snowden, a former US National Security Agency contractor now living in Russia who has been charged with leaking secret information.

On Saturday, Trump said he was considering a pardon for Snowden, who gave a trove of secret files in 2013 to news organisations that disclosed vast domestic and international surveillance operations carried out by the NSA.

Last month, Trump used his presidential power to commute the sentence of long-time friend and adviser Roger Stone, who was convicted of lying under oath to lawmakers investigating Russian interference in the 2016 US election.