Kristi Noem, the United States Secretary of Homeland Security, is set to resign on March 31 as announced by President Donald Trump via his social media platform, Truth Social. This marks Noem as the first member to exit Trump’s second administration. Trump indicated that Republican Senator Markwayne Mullin from Oklahoma will be nominated as her replacement, although he will initially assume the role of acting secretary while awaiting Senate confirmation. Noem's resignation comes after a tumultuous period in which she oversaw highly controversial immigration enforcement practices that attracted significant public backlash and legal challenges. These actions have been heavily scrutinized, and her departure could signal a shift in how the department approaches immigration policy moving forward. Trump lauded Noem for her accomplishments, especially pointing to her work at the border, where she has implemented strict measures aimed at reducing illegal immigration. Furthermore, Trump has stated that Noem will take on a new role as a special envoy for an initiative called "Shield for Americas," aimed at addressing security concerns in the Western Hemisphere. This indicates that despite her resignation from the Homeland Security position, Noem will still play a significant role within Trump's framework, potentially shaping U.S. foreign policy in the region.