Donald Trump revived his attacks on President Obama’s "double standard" on foreign affairs and joked about calling Sen. Elizabeth Warren (D-Mass.) “Pocahontas" during his first television interview since firing his campaign manager, staying true to form even as he vowed to run "a different kind of campaign."

Trump on Monday signaled his intention to recalibrate after several tumultuous weeks, letting go campaign manager Corey Lewandowski and consolidating power with chief strategist Paul Manafort. Speaking to Fox News' Bill O'Reilly Monday evening, Trump said political observers could expect "little different style" as the campaign pitches forward toward the general election.

When Fox News’ Bill O’Reilly pressed Trump about his previous insinuations that Obama sympathized with terrorists — which he said in the wake of the mass shooting at an LGBT nightclub in Orlando — the real estate mogul balked but continued to accuse Obama of a "double standard" when dealing with Iran.

“I don’t believe it," he told O'Reilly when asked about the comments. "I do say, though, when I see a deal like was made with Iran, this horrible, horrible deal … I look at things and I see what’s going on."

“I don’t believe anything. I see things,” he said in another instance. “I mean, it’s not a question of what I think. But you look at facts. This isn’t thinking, this is facts.”

O’Reilly pressed Trump on the comments, citing Trump’s past “birther” accusation that President Obama may not have been born in the United States, which critics say was a racially motivated attack.

"Well,” Trump responded, “it bothers me when he's afraid or doesn't want to mention radical Islamic terrorism when obviously that's what it was."

Asked about the staff shake up, Trump praised Lewandowski and said did a good job navigating the campaign through the primary election — but added that he was not up to running a general election campaign.

“He was terrific toward me. Said I was a talented person. And he’s a talented person. He’s a good guy. He’s a friend of mine. But I think it’s time now for a different kind of a campaign,” Trump said. “We ran a small, beautiful, well unified campaign. It worked very well in the primaries.”

“I’m really proud of him. He did a great job,” he added. “But we’re going to go a little bit of a different route from this point forward. A little different style. He’s a good guy.”

Trump joked about calling Sen. Elizabeth Warren "Pocahontas" during the interview, a derogatory term he has used to mock Warren’s claim to Native American ancestry. He has been criticized for using the nickname and accused of racial insensitivity.

“I do regret calling her Pocahontas because I think it’s a tremendous insult to Pocahontas,” Trump said, cribbing a punch line he has said on the campaign trail. “So, to Pocahontas, I would like to apologize to you.”

Trump indicated that he was interested in keeping the campaign relatively small compared to Clinton’s, who has more than 10 times as many employees on payroll than Trump’s estimated 70 staffers.

Trump said that he plans to announce his vice presidential pick at the Republican National Convention in July.

“I want somebody that I can rely on for their judgment. Hillary Clinton has poor judgment. I hope she picks a vice presidential candidate with good, but hopefully it won’t matter because she’ll lose, but I want somebody with great judgment,” Trump said.