WASHINGTON, March 7, (AP): US President Donald Trump on Thursday fired his embattled Homeland Security Secretary Kristi Noem, after mounting criticism over her leadership of the department, including the handling of the administration’s immigration crackdown and disaster response. Trump, who said he would nominate Oklahoma Republican Sen Markwayne Mullin in her place, made the announcement on social media after Noem faced a two-day grilling on Capitol Hill this week from GOP members as well as Democrats.

Noem’s departure marks a stunning turnaround for a close ally to the president who was tasked with steering his centerpiece policy of mass deportations. But she appeared to increasingly become a liability for Trump, with questions arising over her spending at her department and over her conduct in the aftermath of the shooting deaths of two protesters in Minneapolis earlier this year.

Trump said Noem "has served us well, and has had numerous and spectacular results (especially on the Border!).” He said he was making her a "Special Envoy for The Shield of the Americas,” a new security initiative that he said would focus on the Western Hemisphere. Noem, who appeared at a law enforcement event in Nashville, Tennessee, moments after Trump's announcement, did not address her ouster there.

She read from prepared remarks and was not asked by attendees about the development. Later, in a social media post, she thanked Trump for the new appointment and touted her accomplishments as secretary. "We have made historic accomplishments at the Department of Homeland Security to make America safe again,” she wrote.

White House press secretary Karoline Leavitt said the administration will work with the GOP-led Senate to get Mullin, whom she called "extraordinarily qualified,” confirmed to lead DHS "as soon as possible.” Noem is the first Cabinet secretary to leave during Trump’s second term. Her tenure looked increasingly short-lived after hearings in Congress this week where she faced rare but blistering criticism from Republican lawmakers.

One particular point of scrutiny was a $220 million ad campaign featuring Noem that encouraged people in the country illegally to leave voluntarily. Noem told lawmakers that Trump was aware of the campaign in advance, but Trump disputed that in an interview Thursday with Reuters, saying he did not sign off on the ad campaign.

Noem has faced waves of criticism as she’s overseen Trump’s immigration crackdown, especially since the shooting deaths of the two protesters in Minneapolis at the hands of immigration enforcement officers. In the immediate aftermath of the deaths of Renee Good and Alex Pretti, Noem portrayed both of them as aggressors, contradicting widely viewed videos and descriptions of their deaths from bystanders. She declined to apologize for her description over two days of Congressional testimony.