President Donald Trump said in a Truth Social post on Friday, March 6, 2026, that Homeland Security Secretary Kristi Noem will leave her post at the end of the month and that he plans to nominate Sen. Markwayne Mullin, a Republican from Oklahoma, to lead the Department of Homeland Security.
Trump framed Noem’s departure as a reassignment rather than a firing, saying she will become a “Special Envoy for The Shield of the Americas,” which he described as a new Western Hemisphere security initiative. He said the change would be effective March 31. The post did not clarify whether that phrase is an official job title or Trump’s description of the assignment.
Trump also said he will nominate Mullin as her successor. As of March 6, the White House had not published additional documentation alongside the post, such as a formal personnel announcement, a nomination transmittal to the Senate, or a directive describing the envoy role or the initiative.
Mullin cannot take over as DHS secretary unless and until the Senate confirms him. Trump did not specify who would run the department day to day during any gap between March 31 and a confirmed successor.
What was announced
In the post, Trump said Noem would move into a new envoy assignment tied to “The Shield of the Americas,” and that Mullin is his intended pick for DHS secretary, with the change set for March 31.
- Outgoing: DHS Secretary Kristi Noem (through March 31, per Trump’s post)
- Incoming nominee: Sen. Markwayne Mullin, R-Okla.
- Date cited by Trump: March 31
Who they are
Mullin is a Republican senator from Oklahoma and a close Trump ally. If nominated, he would face questions about DHS’s broad portfolio, including border and immigration enforcement, disaster response, cybersecurity coordination, aviation security, and critical infrastructure protection.
Noem, a former South Dakota governor, has led DHS during a period when the administration has emphasized border enforcement and expanded coordination with other agencies on fentanyl and cartel-related investigations. The department is also subject to oversight by Congress and watchdog reviews, including the DHS Office of Inspector General and the Government Accountability Office.
Noem’s next job
Noem said in a written statement released by DHS on March 6 that she would continue serving the administration in the envoy job and linked the assignment to counter-cartel work and hemispheric security cooperation.
Key questions about the envoy position have not been answered in public materials. Those include whether it is a Senate-confirmed role, what office would staff it, how it would be funded, and whether it would sit inside DHS or elsewhere in the administration.
Public details about “The Shield of the Americas” also remain limited. The administration has not released a separate fact sheet or directive describing the initiative’s scope, authority, or timeline.
Why the change
Trump did not provide a detailed public explanation beyond describing the move as a reassignment and naming a successor nominee. The administration has not publicly tied the personnel change to any specific inquiry, hearing, or report.
What comes next
If Trump formally sends Mullin’s nomination to the Senate, the next step is the confirmation process. DHS secretary nominations are referred to the Senate Homeland Security and Governmental Affairs Committee, which typically holds a hearing and then votes on whether to report the nomination to the full Senate.
Lawmakers from both parties are likely to press Mullin on DHS priorities, including border enforcement strategy, procurement and contracting controls, oversight and transparency, civil liberties issues, and disaster response readiness.
On interim leadership, DHS transitions are governed by the Federal Vacancies Reform Act and the department’s order of succession. The administration has not publicly stated who would be designated to lead DHS on an acting basis starting March 31 if there is a gap.
Why it matters
Leadership changes at DHS can affect enforcement posture and management priorities, but the shift from announcement to action runs through the Senate confirmation process and federal succession rules.
- Executive control: The president can redirect policy by changing agency leadership.
- Advice and consent: The Senate confirmation process gives lawmakers a structured chance to question a nominee on management, spending, legal limits, and enforcement priorities.
- Oversight: Hearings and document requests can elevate disputes that might otherwise stay inside an agency.
What to watch
Several questions will shape the weeks ahead:
- Is the nomination sent to the Senate? Confirmation cannot begin in earnest until the nomination is transmitted and referred.
- Who serves as acting secretary? Watch for a White House or DHS notice naming an acting leader and citing the relevant authority.
- How fast is the confirmation track? Speed depends on Senate scheduling and how contentious DHS funding and border debates become.
- What is the envoy job? The administration’s rollout of “The Shield of the Americas” should clarify scope, reporting chain, and whether the role carries independent authority or budget.
- What do key senators say? Statements from the committee chair and ranking member, as well as appropriators, can signal how smooth or contentious the process will be.
For now, the headline is straightforward: Trump says Noem will leave DHS on March 31 and that he plans to nominate Mullin to replace her. The operational reality will depend on the confirmation timeline, interim leadership decisions, and what the administration discloses about the new envoy role.
Sourcing: Trump announced the move in a March 6, 2026 Truth Social post. DHS released a written statement from Noem the same day. As of March 6, the White House had not released additional public documentation describing the envoy role, establishing “The Shield of the Americas,” or showing when a formal nomination will be transmitted to the Senate.