WASHINGTON, United States (AFP)—United States (US) President Donald Trump on Thursday fired Kristi Noem as head of the Department of Homeland Security, 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.

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 by the Senate, where Republicans hold a majority.

“Markwayne will work tirelessly to Keep our Border Secure, Stop Migrant Crime, Murderers, and other Criminals from illegally entering our Country, End the Scourge of Illegal Drugs and, MAKE AMERICA SAFE AGAIN,” Trump said.

– Deportation policy –

The Republican president campaigned for the White House on a pledge to remove millions of undocumented migrants from the United States and DHS is the chief enforcer of his deportation policy.

Noem came in for bipartisan criticism at Tuesday’s Senate hearing over the Trump administration’s immigration crackdown.

“Under your leadership, the Homeland Security Department has been devoid of any moral compass or respect for the rule of law,” Senator Dick Durbin, a Democrat from Illinois, told Noem.

Durbin and other Democrats repeatedly asked Noem to apologize for the deaths of two Americans shot dead by federal agents in Minnesota during protests against the immigration crackdown and for calling them “domestic terrorists.”

Senator Thom Tillis, a Republican from North Carolina, had harsh words for Noem’s tenure at DHS and called for her resignation.

“What we’ve seen is a disaster under your leadership,” Tillis said. “What we’ve seen is innocent people getting detained that turn out are American citizens.”

Senator John Kennedy, a Republican from Louisiana, questioned Noem about the $220 million spent by DHS on television advertisements urging undocumented migrants to self-deport.

Noem said the advertisement campaign had been “effective.”

“They were effective in your name recognition,” Kennedy shot back.

Noem’s firing comes amid a partial shutdown at DHS.

Democrats oppose any new funding for DHS until major changes are implemented to how the Immigration and Customs Enforcement (ICE) agency conducts its operations.

They have demanded curtailed patrols, a ban on ICE agents wearing face masks and a requirement that they obtain a judicial warrant before entering private property.