US President Donald Trump on Thursday fired Kristi Noem as head of the Department of Homeland Security (DHS), the agency responsible for carrying out his sweeping immigration crackdown. According to multiple media reports, Trump was upset with Noem’s testimony at a Senate hearing this week where she said the president had approved a $220 million DHS advertising campaign in which she featured prominently. Trump in a post on Truth Social said Markwayne Mullen, a Republican senator from Oklahoma, would take over from Noem at the powerful department on March 31. Read more‘I spent almost four months in a prison cell’: Journalist Mario Guevara on covering ICE The president said Noem, 54, would become his special envoy for a new security initiative in the Western Hemisphere he called “The Shield of the Americas”. Noem “has served us well, and has had numerous and spectacular results (especially on the Border!)”, Trump said. Trump described Mullin as a “MAGA Warrior” and said he will be a “spectacular Secretary of Homeland Security”. Mullin’s nomination will be subject to confirmation …