ABC News reported in November that Nauert had been offered the United Nations job, but it was not clear at the time whether she had accepted.
Former President Barack Obama's United Nations ambassadors, Susan Rice and Samantha Power, had the designation, as did Haley, who came to the role after being South Carolina's governor.
During her tenure as a State Department spokeswoman, Nauert largely stuck to the department's official script, often deflecting questions about USA allies, including Israel.
Nauert's appointment would reinforce the link between Fox News and Trump, who has been accused of turning to the conservative-leaning channel, rather than experts, for policy advice.
Mr. Trump told The Washington Times in an interview last month that Ms. Nauert was "under strong consideration" for the post, but he was evaluating other candidates. Trump, who has repeatedly criticized the UN, may want a more junior person in the role so as to de-emphasize the importance of the relationship between the United States and the United Nations.
It's likely that she'll also be asked to answer for the Trump administration's scorn for global bodies, including the UN, Bloomberg News reported.
To take over the Cabinet role, Nauert will need to be confirmed by the Senate.
Aaron David Miller of the Wilson Center says Nauert has a different profile from past US ambassadors to the United Nations. She oversaw public diplomacy in Washington and all of the roughly 275 overseas USA embassies, consulates and other posts.
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He noted all the major American players attended the Argentina meeting, giving a sign of "buy in" on a USA position. President Donald Trump a day after he warned of more tariffs if the two sides could not resolve their differences.
And, last but not least, no one would deny Nauert's attractiveness, which seems crucial in the noble role of being the "US face" and White House policy mouthpiece overseas, doesn't it? She hadn't specialized in foreign policy or worldwide relations.
But her inexperience sometimes shone through: in June she cited the D-day landings as evidence of the longstanding relationship between Washington and Berlin.
Like Haley, a former SC governor, Nauert would come to the job with little experience in diplomacy.
Pompeo, Nauert's current boss, recently delivered a speech attacking multinational institutions and agreements that many believe have served as pillars of stability in the post-World War II era.
Two administration officials confirmed Mr Trump's plans on Thursday.
Pompeo tweeted that Nauert has travelled with him since he took the helm of the State Department.
"And one of his favourite shows is the popular morning show, Fox and Friends, and Nauert was associated with this show for several years, and that surely had something to do with her selection".
Here are the top facts that could provide an exhaustive look at the United States president's pick for the top UN role, largely seen as a stepping stone to assuming more senior roles in government.