Former United Nations Ambassador John Bolton said Thursday that his appointment as national security adviser by President Donald Trump is "still sinking in" and that before he takes office next month, "I'll be devoting myself to getting ready to fill in for H.R."
"I didn't expect that announcement this afternoon," Bolton, 69, a Fox News commentator, told Martha MacCallum in an interview on the network. "But it's obviously a great honor and always an honor to serve our country."
Bolton, who served Republican Presidents Ronald Reagan and both Bush 41 and 43, will replace H.R. McMaster on April 9, Trump announced on Twitter.
McMaster, 55, a three-star Army lieutenant general, said he would "leave public service" after retiring from active duty this summer.
Bolton said President Trump offered him the position earlier Thursday in a visit to the White House after weeks of news reports speculating that he would replace McMaster.
"It came to a conclusion this afternoon," he told MacCallum. "There's still a transition.
"I look forward to working with H.R. and his team and the other senior members of the president's team on national security.
"I have no doubt there's a lot of work to do."
Bolton, who considered running for president in 2012 and 2016 and has long been hawkish on foreign affairs, said that his previous positions — as a private citizen or opining on Fox — were now "behind me."
"I've never been shy about what my views are," he told MacCallum. "Frankly, what's said in private now is behind me, at least effective April 9.
"The important thing is what the president says and what advice I give him."
However, Bolton did not hold back on the leaks surrounding President Trump's congratulatory call Tuesday to Russian President Vladimir Putin, saying he was "outraged" by the press disclosures.
"It's completely unacceptable," he said.
"You cannot conduct diplomacy and expect other foreign leaders to be candid and open in their conversations with the president if some munchkin in the executive branch decides they're going to leak the talking points of the transcript or any other aspect of it.
"This is really a terrible reflection on the individual or individuals that did this," he added. "They should be ashamed of themselves.
"Whether you're a Republican or a Democrat, a liberal or conservative, there ought to be unity such that leaking of that sort is simply unacceptable."
On Trump congratulating Putin for his re-election, despite being warned not to by national security advisers, Bolton said: "I don't consider it a significant point one way or the other.
"I've said 'congratulations' to a lot of foreign diplomats and officials," he told MacCallum. "It's a matter of being polite.
"It's a matter of courtesy more than anything else."
Regarding reports that Trump and McMaster differed on various national security issues, Bolton said that the president needed a "free interchange of ideas" among his advisers.
"I have my views. I'm sure I'll have a chance to articulate them to the president.
"Some people don't like people that have substantive views," Bolton said. "They're more processed-oriented.
"If the government can't have a free interchange of ideas among the president's advisers, I think the president is not well-served.
"The national security adviser, like all of the president's top advisers, serve at his pleasure," Bolton later added.
"He may be a different kind of president than others, but I think that's what the people voted for.
"That's the role I've been asked to take on, that I sought, certainly.
"I'm pleased to have accepted it and honored to carry it out," he added. "We'll see what happens."