Mr Trump’s comments on Twitter came a day after lawyer Rudy Giuliani played down the possibility that the president could pardon himself, suggesting he might have that authority but would be unwise to use it.
“Pardoning himself would be unthinkable and probably lead to immediate impeachment,” Mr Giuliani, a member of Mr Trump’s legal team, told NBC’s Meet The Press.
“And he has no need to do it, he’s done nothing wrong.”
On Twitter, Mr Trump said: “As has been stated by numerous legal scholars, I have the absolute right to PARDON myself, but why would I do that when I have done nothing wrong?”
He then again decried special counsel Robert Mueller’s probe as a “never ending Witch Hunt”.
Mr Trump later added that the “appointment of the Special Councel is totally UNCONSTITUTIONAL! Despite that, we play the game because I, unlike the Democrats, have done nothing wrong!”
The president’s legal team has made clear that it will combat any effort to force the president to give evidence in front of a grand jury.
Mr Giuliani underscored one of the main arguments in a newly unveiled letter sent by Mr Trump’s lawyers to Mr Mueller back in January: A president cannot be given a grand jury subpoena as part of the investigation into foreign meddling in the 2016 election.
But Mr Giuliani, in a series of television interviews, broke with one of their bolder arguments in the letter that a president could not have committed obstruction of justice because he has ultimate authority over any federal investigation.
Yet the former New York City mayor, who was not on the legal team when the letter was written, added that Mr Trump “probably does” have the power to pardon himself, an assertion challenged by legal scholars.
He said the president’s legal team has not discussed that option, which many observers believe could plunge the nation into a constitutional crisis.
“I think the political ramifications would be tough,” Mr Giuliani told ABC’s This Week.
“Pardoning other people is one thing, pardoning yourself is tough.”
Mr Trump has issued two unrelated pardons in recent days and discussed others, a move that has been interpreted as a possible signal to allies ensnared in the Russia probe.
The letter is dated January 29 and addressed to Mr Mueller from John Dowd, a Trump lawyer who has since resigned from the legal team.
Mr Mueller has requested an interview with the president to determine whether he had criminal intent to obstruct the investigation into his associates’ possible links to Russia’s election interference.
Mr Giuliani said a decision about an interview would not be made until after Mr Trump’s summit with North Korean leader Kim Jong Un on June 12 in Singapore, and he cast doubt that it would occur at all.
“I mean, we’re leaning toward not,” Mr Giuliani told ABC.
“But look, if they can convince us that it will be brief, it would be to the point, there were five or six points they have to clarify, and with that, we can get this long nightmare for the American public over.”