Transcript for Melania Trump issues rare public attack against WH aide

that looming shake-up in the white house. An unhappy president trump signaling major new moves as the first lady issues a rare public attack calling for a top national security official to be fired. Our chief white house correspondent Jon Karl tracking it all. In the wake of the midterms a lot of tumult in the west wing. Reporter: No question about that. The president is actually keeping a low profile over the last few days but there are indications that he is about to shake things up in the west wing. There are signs of major changes coming from the white house. Multiple senior officials tell ABC news the president is poised to fire homeland security secretary kirstjen Nielsen in the coming weeks. The president has complained privately she's been too weak on illegal immigration. And officials believe that if she goes, her ally in the west wing, chief of staff John Kelly will likely go too. All of this as the notoriously private first lady is asserting herself in a way she never has before. Taking aim at a key player on the president's west wing staff, the first lady called for the firing of deputy national security adviser Mira ricardel. It's the position of the office of the first lady that she no longer deserves the honor of serving in this white house. The first lady's spokesperson said this in a written statement. It came less than an hour after ricardel was seen smiling over the president's shoulder at a white house event. White house sources tell ABC news the first lady became irritated with ricardel over the planning of her Africa trip last month and that she felt ricardel treated her staff with disrespect. On that trip, the first lady told ABC's Tom llamas there were people on the president's staff that she did not trust. He's been in office now almost two years. Has he had people that you didn't trust working for him? Yes. Did you let him know? I let him know. And what did he do? Some people they don't work there anymore. Reporter: Despite the first lady's extraordinary call for her ouster, ricardel still has a job here at the white house, at least for now. In fact, George, there are senior officials here actively defending her including one that pointed out she is one of the most -- one of the highest ranking women in the trump administration and that, by the way, she's never actually met the first lady. Never met her, wow. A lot of in-fighting going on and, Jon, previously chief of staff John Kelly said he would stay as chief of staff through 2020 but a lot of intense jockeying to replace him. Reporter: Absolutely. The leading candidate right now appears to be Nick ayers, the chief of staff to vice president pence, 36 years old but has extensive experience in the political realm but there will be a fight over this position just as there is a fight over every position in this white house, one other name I have heard mentioned is treasury secretary Steven mnuchin. That would be a big move. Jon Karl, thanks very much.

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