President Donald Trump fired Homeland Security Secretary Kristi Noem on Thursday, making her the first Cabinet secretary to leave her post and capping off a tumultuous year in which she oversaw his increasingly unpopular mass deportation agenda.
Alongside the announcement of Noem’s ouster, Trump said he would tap Sen. Markwayne Mullin, R-Okla., to replace her, elevating a fiercely loyal first-term senator.
“I am pleased to announce that the Highly Respected United States Senator from the Great State of Oklahoma, Markwayne Mullin, will become the United States Secretary of Homeland Security (DHS), effective March 31, 2026,” Trump wrote on Truth Social.
He added that Noem, who he said “has served us well,” will take over a new role called “Envoy for The Shield of the Americas.” He described the position as one that will lead “our new Security Initiative in the Western Hemisphere.”
Trump spoke to Noem about the job switch Thursday afternoon, according to two people familiar with the conversation. Noem is traveling outside Washington.
An administration official told NBC News that Trump decided to fire Noem because of “a culmination of her many unfortunate leadership failures including the fallout in Minnesota, the ad campaign, the allegations of infidelity, the mismanagement of her staff, and her constant feuding with the heads of other agencies, including CBP and ICE.”
The official added: “Kristi’s drama sadly overshadowed and distracted from the Administration’s extremely popular immigration agenda, which will continue full force.”
Noem thanked Trump on X for her new position and touted her tenure as DHS secretary.
"In this new role, I will be able to build on the partnerships and national security expertise, I forged over the last 13 months as Secretary of Homeland Security," she added before she included a list of "historic accomplishments," at the department.
Corey Lewandowski, a close aide and adviser to Noem, is also expected to leave DHS, according to an administration official.
Lewandowski, who was one of the first staff members on Trump’s 2016 campaign for president, faced scrutiny from lawmakers over his role at the department, including over whether he had the power to approve grants and contracts. In congressional hearings this week, Noem, who is married, faced questions about their personal relationship.
Mullin told reporters at the Capitol on Thursday that he was “super excited about this opportunity” and that it was “not a complete surprise.”
He added, “The president and I, as you guys know, we’re great friends, and we get along great. I look forward to working with him in his Cabinet. Of course, we’ve still got to go through this little thing called confirmation, and we’re going to get started on it right away.”
Mullin was at a Senate Republican lunch Thursday when he appeared to get a phone call, then “abruptly” got up and rushed out of the room — leaving a “full plate of food behind,” according to Sen. Roger Wicker, R-Miss., who said it raised suspicion among Republicans that something was afoot.
Mullin was spotted leaving the lunch using one hand to press the cellphone to his ear and the other to cover his mouth, as if he was trying to shield the conversation from reporters, and then ducked into the leadership office of Sen. John Barrasso, R-Wyo., just around the corner from the room where the GOP lunch was being held.
Mullin later said the phone call came from the White House switchboard, so he didn't see Trump's name pop up on the caller ID.
“I’ve got to be honest with you, I wasn’t expecting the call today,” he said.
White House press secretary Karoline Leavitt called Mullin "extraordinarily qualified" on X and said the White House will work with the Senate to confirm him "as quickly as possible."
Mullin, a former MMA fighter, served for a decade in the House before he won a 2022 special election to the Senate. If he is confirmed as DHS secretary, Oklahoma Gov. Kevin Stitt would be required to choose another Republican to fill the vacancy until the November midterm elections. Because Mullin’s Senate term expires this year, state law notes, there wouldn’t be a special election to replace him.
Shortly after Trump’s post Thursday, Noem delivered the keynote address at the Sergeants Benevolent Association Major Cities Conference in Nashville, Tennessee, and did not address that she would be stepping down this month.
“I appreciate your wisdom and your advice as we continue to develop trainings and insight into how leadership can work together to make good decisions and to break down the silos between agencies so that we can work together in better ways than we have in the past,” she told law enforcement officers.
Noem has been at the forefront of Trump’s signature policy agendas: deporting immigrants, restricting immigration and clamping down on the U.S.-Mexico border. She is the first Cabinet secretary to step down in Trump’s second term. Last year, Mike Waltz left his Cabinet-level post as national security adviser after Trump nominated him to become ambassador to the United Nations.
Noem's place in the administration became increasingly unstable after federal agents shot and killed two U.S. citizens during immigration operations in Minneapolis, her relationship with the Coast Guard, the only branch of the military under her command, began fraying and she made comments this week before lawmakers that rankled Trump.
In the congressional hearings Tuesday and Wednesday, lawmakers questioned Noem about the $200 million ad campaign she oversaw that urged anyone in the U.S. illegally to deport voluntarily. The ad campaign, which was conducted mostly in English, featured Noem. According to AdImpact, an ad-tracking firm, DHS has spent almost $80 million to air the ads since the start of 2025, not including the cost of production.
Noem told the Senate Judiciary Committee on Tuesday that Trump approved the multimillion-dollar ad campaign, a claim the White House denied.
“POTUS did not sign off on a $220 MILLION dollar ad campaign. Absolutely not,” a White House official told NBC News on Thursday.
At the Senate and House hearings this week, Noem also faced questions from lawmakers about the administration’s actions in Minneapolis. The deployment of thousands of federal troops to conduct immigration enforcement activities, using at times brutal tactics, has led to intense bipartisan criticism of Noem’s leadership of DHS.
Noem declined to apologize for calling Renee Good and Alex Pretti, two Americans who have been killed by federal agents, “domestic terrorists,” though she conceded that investigations into the two deaths continue.
Republican Sens. Thom Tillis of North Carolina and Lisa Murkowski of Alaska called for Noem to step down in January, with Tillis telling reporters he couldn’t “think of any point of pride over the last year” of her tenure.
Before she served in the Trump administration, Noem was the governor of South Dakota.
