The president, who puts a premium on loyalty, earlier hailed Nauert as "a supporter for a long time - really, excellent".
CNN, while citing her "precipitous rise" since arriving at the state department, also speculates how the Democrats are likely to "grill Nauert" on her qualifications for the position.
Is Nauert up for the new role?
"I think that he will be confirmed readily by the Senate", Gingrich said. Here are three takeaways from Nauert's nomination.
Conservative lawmakers railed against former President Barack Obama for, as they put it, running foreign policy and national security out of the Oval Office. If confirmed by the Senate, she would be a leading administration voice on Trump's foreign policy.
Ms Nauert, who became State Department spokeswoman under former secretary Rex Tillerson, did not respond to requests for comment.
Schaefer notes, though, that Trump already has a team in place that he relies on for help in crafting foreign policy -Pompeo and National Security Adviser John Bolton.
The interview also provided no new insight into why she resigned, in a move that reportedly "shocked" the administration's top officials.
Pompeo was scathing about the United Nations in a speech this week in Brussels.
The president said Nauert is "somebody that we know very well" and "has done a great job" as the State Department's press secretary.
Nauert became an anchor on Fox & Friends, Trump's favourite television talkshow, where she helped air the network's recurrent themes about the threat of immigration, warning that immigrant children arriving in the U.S. could be bringing disease into the country, and that Sharia law was spreading in urban areas with Muslim populations. And that's the point: Trump values how his messages and policy decisions are explained by his subordinates, and has said his instincts and intellect are better than most.
Aaron David Miller of the Wilson Center says Nauert has a different profile from past US ambassadors to the United Nations.
Nauert was a Fox News anchor who was then hired by Trump to be the State Department spokeswoman.
Haley announced in October she would step down at the end of the year from her post at the United Nations, stirring speculation about the popular Republican's political future.
"I don't think Haley is thinking about running in 2020. She needs to go make some money to pay down some debts", one GOP strategist recently told Roll Call.
She's been a strong defender of Trump's at the podium, something he has clearly noticed.