Updated

President-elect Donald Trump is expected to select South Dakota Gov. Kristi Noem to fill the role of Homeland Security secretary, multiple sources confirm to Fox News Digital.

Noem, who was thought to be a potential running mate on the Trump ticket earlier in the year, has served as governor of the Mount Rushmore State since 2019.

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Kristi Noem

President-elect Donald Trump is expected to select South Dakota Gov. Kristi Noem to fill the role of Homeland Security secretary, according to reports on Tuesday. (KAMIL KRZACZYNSKI/AFP via Getty Images)

The Department of Homeland Security oversees U.S. Customs and Border Protection, Immigration and Customs Enforcement, U.S. Secret Service and the Federal Emergency Management Agency (FEMA).

If selected, Noem would work with Tom Homan, who was announced as Trump's "border czar" on Sunday, and Stephen Miller, who was announced as the White House deputy of staff for policy on Monday.

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Noem, along with Homan and Miller, has long been a supporter of Trump's hardline stance on immigration and border security. 

As governor, Noem has dispatched troops from the South Dakota National Guard multiple times to serve along the U.S. southern border with Mexico.

"I was the very first governor that when Texas and Arizona asked for help, I sent my National Guard troops down there to help," Noem touted at her CPAC Dallas speech in the summer of 2021.

Fox News also confirmed on Monday night that the president-elect is expected to choose Republican Sen. Marco Rubio of Florida as Secretary of State.

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An official announcement from Trump's transition team on either Rubio or Noem had not been made as of Tuesday morning.

Noem, Trump

Earlier in the year, Noem was thought to be one of Trump's top contenders for vice president. (KAMIL KRZACZYNSKI/AFP via Getty Images)

Noem, who served eight years as South Dakota's at-large congresswoman before winning election as governor in 2018, has long been a strong Trump supporter and ally.

And the governor, who speaks regularly with Trump according to those in her political orbit, was a high-profile surrogate on behalf of the former president on the campaign trail this year.

In an interview last week on Fox News' "Your World," Noem told host Neil Cavuto that Trump "has told me several times now, a couple of times just since Election Day, about how focused he is on doing big things…he knows he only has four years and he wants to hit the ground running. And he said anybody that I want around me needs to be thinking big, too."

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Noem, who was convincingly re-elected in 2022, is term-limited and has two years left in office as South Dakota governor.

The news of Trump's selection of Noem to serve at Homeland Security was first reported by CNN.