U.S. President-elect Donald Trump has chosen South Dakota Governor Kristi Noem to serve as the next Homeland Security Secretary, two sources familiar with the decision said on Tuesday.

Noem, once seen as a possible running mate for Republican Trump, is currently serving her second four-year term as South Dakota's governor after a landslide reelection victory in 2022. She rose to national prominence after refusing to impose a statewide mask mandate during the COVID-19 pandemic.

Noem faced widespread backlash in April when she wrote in a memoir that she shot to death an "untrainable" dog that she "hated" on her family farm. Some Trump advisers said they believed Noem's stock fell in the former president's eyes after that, at a time when she was still a vice presidential contender.

Both Trump's campaign and Noem's office did not immediately respond to requests for comments.

The Department of Homeland Security is responsible for everything from border protection and immigration to disaster response and the U.S. Secret Service.

Trump on Monday appointed Tom Homan as his administration's incoming "border czar". Homan said he will prioritize deporting illegal immigrants who pose threats to public safety and national security.

Sources told Reuters on Monday that Trump was expected to tap U.S. Senator Marco Rubio to be his secretary of state.