President Donald Trump has fired his Secretary of State Rex Tillerson and is replacing him with CIA director Mike Pompeo, who is set to be succeeded by Gina Haspel, deputy director at the Central Intelligence Agency.Trump told reporters Tuesday morning he and Tillerson "have been talking about this for a long time," and they "got a long quite well", but they have different mindset and different thinking.For instance, the president said they did not agree on the 2015 Iran nuclear agreement."When you look at the Iran deal, I think it's terrible, I guess he thought it's okay," he said. "I want to either break it or do something and he felt a little bit differently, so we were not really thinking the same."During the Obama administration, the U.S. and other major powers struck the deal in which Tehran agreed to limit its nuclear program in exchange for the easing of international economic sanctions. President Trump has repeatedly criticized the agreement as a bad deal and threatened to dismantle it.By contrast, Trump said he and Pompeo are more like-minded."With Mike Pompeo, we have a very similar thought process, I think it's going to go very well," he said, adding "Mike Pompeo will be a truly great Secretary of State, I have total confidence in him."Trump also pointed out he did not discuss much with Tillerson regarding his decision to meet with North Korean leader Kim Jong Un. "I made that decision by myself, Rex wasn't, as you know, in the country," he said. "I made the North Korea decision with consultations from many people, but I made that decision by myself," he said.A senior White House official said Tuesday Tillerson's ouster occurred at this time because Trump wanted to "have his new team in place in advance of the upcoming talks with North Korea and various ongoing trade negotiations."Earlier Tuesday, Trump thanked Tillerson on Twitter. According to Under Secretary of State Steve Goldstein, Tillerson, who just completed a trip to Africa, planned on staying at the State Department and suggested Tillerson was surprised by his ouster."The Secretary did not speak to the president and is unaware of the reason, but he is grateful for the opportunity to serve, and still believes strongly that public service is a noble calling." Trump and Tillerson have clashed for months over several issues. Tillerson did not dispute reports that he called the president a "moron," leaving that responsibility to State Department Heather Nauert, who maintained Tillerson "does not use that type of language." In a statement issued by the White House, Trump said Pompeo, a former Army calvary officer, is the best candidate for Secretary of State at this "critical juncture.""He will continue our program of restoring America's standing in the world, strengthening our alliances, confronting our adversaries, and seeking the denuclearization of the Korean Peninsula," Trump said. Pompeo said he is "deeply grateful" to the president for the opportunity to serve as the nation's top diplomat.Haspel said she is "humbled" by Trump's confidence in her and added if confirmed, "I look forward to providing President Trump the outstanding intelligence support he has grown to expect during his first year in office." Before Pompeo and Haspel can assume the positions, they must be confirmed by a majority vote in the Senate.VOA State Department correspondent Nike Ching contributed to this report.