Department of Homeland Security Secretary Kristi Noem expressed her appreciation to President Donald Trump after he terminated her as cabinet secretary."Thank you @POTUS Trump for appointing me as the Special Envoy for the Shield of the Americas," Noem wrote Thursday on X, noting that she looked forward to working with Secretary of State Marco Rubio and Defense Secretary Pete Hegseth in the new position.Noem went on to tout her "accomplishments" at DHS."We have made historic accomplishments at the Department of Homeland Security to make America safe again: we delivered the MOST secure border in American history, 3 million illegal aliens have left the U.S., we have located 145,000 children, FEMA delivered disaster relief at a 100% faster rate, we ushered in the golden age of travel, saved the American taxpayer $13 billion and revitalized the U.S. Coast Guard," she said.In a post on Truth Social, Trump revealed that he had nominated Sen. Markwayne Mullin (R-OK) to be the next DHS secretary."A MAGA Warrior, and former undefeated professional MMA fighter, Markwayne truly gets along well with people, and knows the Wisdom and Courage required to Advance our America First Agenda," Trump wrote