Roger Stone also denied having had any contact during the 2016 presidential campaign with Julian Assange, the creator of WikiLeaks, the site that published hacked messages from Trump's Democratic opponents in an apparent bid to influence the election.
Roger Stone, an informal adviser to US President Donald Trump, denied Sunday that the two had discussed a possible presidential pardon at a time when Stone is said to be under mounting scrutiny from prosecutors investigating Russian interference.
"I had no contact with Assange," Stone told ABC's "This Week" program. "We have had no communication with (Assange) whatsoever."
He said he had not been contacted by Robert Mueller, the special prosecutor investigating possible collusion or coordination between Trump's campaign team and Russia.
Asked whether he would expect a pardon from the president if indicted by Mueller, Stone replied, "I've had no discussion regarding a pardon."
But Stone insisted that he would never testify against his longtime friend.
"There's no circumstance under which I would testify against the president, because I'd have to bear false witness against him," he said. "I'd have to make things up, and I'm not going to do that."
Mueller has negotiated cooperation deals with several key witnesses, notably Trump's former lawyer Michael Cohen, in exchange for reduced prison sentences for various charges.
Stone and one of his contacts, Jerome Corsi, are suspected of having had advance knowledge that WikiLeaks would, in the summer of 2016, publish a trove of hacked Democratic emails that would prove damaging to Trump's presidential rival, Hillary Clinton.
The ABC interviewer, George Stephanopoulos, asked Stone about emails in which he reportedly instructed Corsi in mid-2016 to "get to Assange at the Ecuadoran embassy in London and get the pending WikiLeaks email."
But Stone insisted he had broken no law.
"I'm certainly guilty of bluffing and posturing and punking the Democrats," he said, before adding, "Where is the crime?