The Trump administration has chosen counterterrorism expert and former Fox News contributor Morgan Ortagus to be the new State Department spokeswoman, three people with knowledge of the decision told NBC News.

Ortagus, a Naval Reserve officer, would bring significant experience in national security and foreign policy to the role. She will replace Heather Nauert, a former Fox News anchor who had been announced as President Donald Trump's pick for United Nations ambassador but later withdrew herself from consideration.

Ortagus previously served as a public affairs officer for the U.S. Agency for International Development, an independent agency that takes direction from the State Department, according to a biography posted on the website of her consulting firm, GO Advisors. Her tenure included work in Iraq.

She also worked for the Treasury Department in the first term of the Obama administration as an intelligence analyst and as Treasury's deputy U.S. attaché to Saudi Arabia, where her GO Advisors bio says she worked on countering illicit finance.

It's unclear when Ortagus' selection will be formally announced. The three people informed of her selection spoke on the condition of anonymity.

After NBC News' report was published, a Fox News spokeswoman said that the network had ended its relationship with Ortagus as of Thursday.

Ortagus and the State Department didn't respond to requests for comment.

The White House National Security Council had no immediate comment. There was no answer at a phone number listed for GO Advisors.

Ortagus would become the latest in a growing list of Fox News employees hired by the Trump administration, particularly for foreign policy positions. In February, former Fox News reporter Lea Gabrielle was tapped to lead the State Department office for countering global misinformation, and former Fox News executive Bill Shine served as Trump's White House communications director until earlier this month, when it was announced that he was joining Trump's re-election campaign.

National security adviser John Bolton and White House strategic communications director Mercedes Schlapp were also both Fox News contributors before joining the administration. Typically, cable news contributors work part-time for a news network providing on-air commentary and analysis.

Nauert, who has served as spokeswoman since 2017, had been announced by Trump as his pick to replace Nikki Haley as U.S. ambassador to the United Nations. But her nomination was never formally submitted to the Senate, and Nauert withdrew from consideration as news broke about a tax issue involving an immigrant nanny she had hired years earlier.

State Department officials told NBC News at the time that Nauert learned after the fact that taxes hadn’t been paid for the nanny and paid them all retroactively. She said in a statement at the time that “the past two months have been grueling for my family and therefore it is in the best interest of my family that I withdraw my name from consideration.”

Since then, Nauert has remained on staff but has not conducted any televised briefings, and U.S. officials have said she did not intend to remain in the spokeswoman role.

As spokeswoman, Ortagus would become one of the most prominent faces of the Trump administration on foreign policy. The position does not require Senate confirmation.

Ortagus co-founded GO Advisory, according to the firm's website. She has also worked at Standard Chartered Bank advising international clients, and wrote a thesis paper about counterinsurgency during a master's program at Johns Hopkins University.