Transcript for Trump expected to nominate ex-Fox News anchor to UN

He has wanted it for so long too. The white house and president trump appears to zero in on staffing changes for U.N. Ambassador and attorney general. Our chief white house correspondent Jon Karl has the latest. Reporter: Good morning. There are some big changes afoot here at the white house. I am told the president has decided to name -- nominate a former Fox News personality as America's ambassador to the united nations and that he is nearing a decision to nominate a former attorney general as his new attorney general. White house officials tell ABC news the president has decided on state department spokeswoman Heather nauert to be America's voice at the united nations. Nauert came to her current state department job without any government experience and no foreign policy experience either. She was, however, an anchor on "Fox & friends," the president's favorite cable news show. She would replace Nikki Haley who was was a two-term governor of South Carolina and nearly a month after Jeff sessions tearful resignation, sources tell ABC president trump is nearing a decision to nominate William Barr for the role. Barr is already served as attorney general for the elder president bush in the 1990s. Whrr was attorney general, he was Robert Mueller's boss. Are you now directing Mueller? Yes. Reporter: At the time Mueller was the head of the doj criminal justice division. Jeff sessions, a U.S. Attorney at the time, also served under Barr. Barr will be seen as a relatively noncontroversial choice, an establishment choice but there are some things that he will be asked about undoubtedly. One of which last year he suggested that there is more reason to investigate allegations against Hillary Clinton than Russian collusion with the trump campaign. Yeah, he agrees with the president on that. As we've seen the president on a tweet perform about the Mueller investigation, of course, it comes ahead of two big reports expected today from the special counsel, the sentencing memos for Paul manafort and Michael Cohen. Reporter: These are big potentially leading us to get real information as to where Mueller is going with his investigation. He will be describing regardless manafort, why he decided to break up that plea agreement, what manafort has been lying about. If you remember he accused manafort of lying and also what he would like to see in terms of the sentencing of Michael Cohen. This will be two interesting filings. Okay, Jon Karl, thanks very much.

This transcript has been automatically generated and may not be 100% accurate.