President-elect Donald Trump has selected South Dakota Gov. Kristi Noem as his next secretary of the Department of Homeland Security, according to two people familiar with the selection.

Noem will be tapped to take over the agency as two key immigration hardliners — Stephen Miller and Tom Homan — are slated to serve in senior roles, signaling Trump is serious about his promise to crack down on his immigration pledges. With his selection of Noem, Trump is ensuring a loyalist will head an agency he prioritizes and that is key to his domestic agenda.

The department saw an immense amount of turmoil the last time Trump was in office. Then, DHS had five different leaders, only two of whom were Senate-confirmed. The agency has a $60 billion budget and hundreds of thousands of employees.

Noem, who previously was a South Dakota representative, will now be tasked with overseeing a sprawling agency that oversees everything from US Customs and Border Protection and Immigration and Customs Enforcement to the Federal Emergency Management Agency and the US Secret Service.

Noem had once been on Trump’s shortlist for vice president, though her relationship with Trump shifted after the negative rollout surrounding the publication of her book: “No Going Back: The Truth on What’s Wrong with Politics and How We Move America Forward.” In it, she revealed that she once killed her 14-month-old wirehair pointer, Cricket, when she was not displaying the signs of an ideal hunting dog.