Nauert, a native of Rockford, Illinois, also worked at State as the acting undersecretary for public diplomacy and public affairs.
If she gets the job, Nauert would take the post with less clout than Haley, a former SC governor who announced in October that she would step down at the end of this year.
Plucked from Fox by the White House to serve as State Department spokeswoman, Nauert catapulted into the upper echelons of the agency's hierarchy when Tillerson was sacked in March and replaced with Mike Pompeo.
Nauert was mostly a polished and unflappable defender of administration policy, smoothing over frequent rifts between the Trump's first secretary of state, Rex Tillerson, and the White House. "We obviously have a very long history with the Government of Germany, and we have a strong relationship with the government, and so we want to reaffirm the strength of our relationship with Germany".
Fox News has been a consistent supporter of the president and he often cites its news.
"I told her, 'God made you handsome".
Watch the clip above, via The Washington Post. "There are a lot of gorgeous people with only one thing to say who vanish from the scene".
She has been the front runner for the United Nations post for some weeks and last month President Trump said she was under "under very serious consideration".
That role gave her responsibilities far beyond the news conferences she held in the State Department briefing room.
"Our foreign policy is a mess and the president was laughed at through his last speech to the UN", Senate Foreign Relations member Christopher S. Murphy, D-Conn., told CNN.
Nauert, who did not have a good relationship with Tillerson and had considered leaving the department, told associates at the time she was taken aback by the promotion offer and recommended a colleague for the job.
"The balance between Nauert's ambition and autonomy will be interesting", Ashish Pradhan, the International Crisis Group's senior United Nations analyst, said.
"Now in terms of formulating policy, I suspect that she is not going to play the role that Nikki Haley did as ambassador to the United Nations", Schaefer said.
Heritage Foundation fellow Brett Schaefer said Nauert has proven she has the ability to explain and defend USA foreign policy, the core requirement for being a US ambassador to the world body. Even more so if the skill is coupled with a wide, snow-white smile, precisely like Nauert's.