KEILAR: In just a few minutes, incoming National Security Adviser John Bolton will meet Defense Secretary James Mattis at the Pentagon, and this will be the first time that the two will met. Mattis said earlier this week that he's looking forward to a partnership with Bolton. CNN's Barbara Starr is live for us from the Pentagon. So Barbara, they have very different views when it comes to foreign policy. What is this going to mean?</s>BARBARA STARR, PENTAGON CORRESPONDENT: Well, they do have differing world views so the first item of business really in Mattis' mind apparently is for them to get to know each other. They've actually never met before. So Bolton coming here to the Pentagon meeting with the defense secretary, and I think it's fair to say they're going to take the size of each other, look at each other's views, how they might get along, have an initial conversation. The big issue on the table? North Korea. I mean, Secretary Mattis has very much said that diplomacy leads the way on North Korea. He's been saying that for months. Mr. Bolton a much more hawkish view about the potential need for war with North Korea. On Iran, Mr. Bolton not in favor of the Iran nuclear agreement. Secretary Mattis has several generals telling him that the Pentagon needs to advocate for staying in the agreement. So it's a combination of having differing world views. Not sure how much it may change Mr. Mattis' access to the president with a new national security adviser in the White House. A long way to go in figuring out what it all means. They're talking about teamwork, but we'll see how it plays out. Brianna?</s>KEILAR: Barbara Starr, thank you so much. And thank you for joining me at this hour. Wolf starts right now.
John Bolton and Mattis to Meet at Pentagon.