President Donald Trump has revealed that Kristi Noem will step down from her position as Secretary of Homeland Security at the conclusion of this month, with Oklahoma Senator Markwayne Mullin named as her successor.
In a statement released on Truth Social, the president confirmed that Mullin, a Republican described as “highly respected,” will assume leadership of the department on 31 March 2026.
Mullin, who has a background in mixed martial arts, previously spent a decade as a House representative before his 2023 special election victory to the Senate. He informed the media that he received notification of his new appointment only moments before the public announcement.
Noem, praised by Trump for having “served well,” is set to transition into a fresh capacity as the “Envoy for The Shield of the Americas.” Trump explained that this role will oversee a new security programme focused on the Western Hemisphere.
This transition represents the first time a Cabinet secretary has resigned during Trump’s second term, following the departure of national security adviser Mike Waltz, who left his post last year to serve as the United Nations ambassador.
During her tenure, Noem was a central figure in implementing the administration’s core policies, such as the tightening of the US-Mexico border and large-scale immigration enforcement.
However, her leadership came under scrutiny following the fatal shootings of two US citizens, Renee Good and Alex Pretti, by federal officers during operations in Minneapolis.
Noem has faced significant bipartisan condemnation for the perceived “brutal tactics” used by federal forces and has refused to retract her description of the two individuals as “domestic terrorists,” despite ongoing inquiries into their deaths.
Her position was further weakened by a $200 million advertising initiative she managed, which encouraged undocumented residents to leave the country voluntarily.
Although Noem testified that the President had sanctioned the multimillion-dollar project, White House officials have since denied that he gave formal approval.
Since the beginning of 2025, the Department of Homeland Security has reportedly spent approximately $80 million on broadcasting these advertisements.
Internal pressures also mounted due to strained relations between Noem and the US Coast Guard, the sole military entity under her department’s jurisdiction.
By January, Republican Senators Lisa Murkowski and Thom Tillis had already demanded her resignation, with Tillis noting a lack of significant achievements during her year in the role. Prior to her Cabinet appointment, Noem was the governor of South Dakota.
