Roger J. Stone Jr., a longtime adviser to President Trump, said on Sunday that he was “prepared to fight for my life” and prove his innocence in the case brought against him by the special counsel, Robert S. Mueller III.
Mr. Stone, who was charged on Friday with obstruction of justice, witness tampering and making false statements, said on ABC News’s “This Week” that text message exchanges that were cited in his indictment were being misrepresented.
“It has to be seen in context,” Mr. Stone said of his exchanges with Randy Credico, a former associate and political gadfly. “It is a humorous exchange. They’re taking things out of context to present them in a light that mischaracterizes their significance. I never told Mr. Credico to lie.”
Mr. Stone told Mr. Credico in 2017 to “do a ‘Frank Pentangeli’” when he appeared before the House Intelligence Committee investigating Russian interference in the 2016 election. The reference was to a character in “The Godfather: Part II” who ultimately avoids implicating another person in his own testimony before Congress.
“If you testify you’re a fool,” Mr. Stone said in one message, according to the indictment, and added: “I could never get away with a certain my Fifth Amendment rights but you can. I guarantee you you are the one who gets indicted for perjury if you’re stupid enough to testify.”
Mr. Stone’s legal team has said that other text exchanges reveal that he and Mr. Credico often had jocular back and forths, before and after the ones in question, that undercut the notion that Mr. Credico could have felt threatened.
Mr. Stone said he had forgotten about some exchanges with Mr. Credico when he told House investigators that they did not exist, a statement that was part of the indictment against him.
“I did forget on some occasions that I had text messages and emails,” Mr. Stone said. “I am human and I did make some errors, but they’re errors that would be inconsequential in the scope of this investigation.”
Mr. Stone also said that he never spoke with Mr. Trump about WikiLeaks, and that they did not discuss a pardon or the investigation into collusion with Russian officials.
According to the indictment, a top official from the Trump campaign dispatched him to get information from the group about the thousands of hacked Democratic emails that were damaging to Hillary Clinton’s presidential campaign.
In a tweet over the weekend, Mr. Trump appeared to put some distance between himself and Mr. Stone, saying that his adviser did not work for the campaign for most of 2016.
On Sunday, Mr. Stone did not rule out the possibility of speaking with Mr. Mueller’s investigators.
“If there’s wrongdoing by other people in the campaign that I know about, which I know of none, but if there is I would certainly testify honestly,” he said.
“I’d also testify honestly about any other matter, including any communications with the president,” he continued. “It’s true that we spoke on the phone, but those communications are political in nature, they’re benign, and there is — there is certainly no conspiracy with Russia,” he said.
Mr. Stone also acknowledged that it was unusual for a defendant who has been arrested to promptly go on a media tour. But Mr. Stone, who has never shied from attention, said he wanted to highlight what he called the “extraordinary” tactics and aggression that the F.B.I. used in its predawn raid on his Florida home.
“I think the American people need to hear about it,” said Mr. Stone, who noted that he is 66, owns no firearms and has an expired passport.
“I was not a flight risk,” he said.