It is not yet clear who would take over her role as State Department Spokesperson.
Outgoing UN Ambassador Nikki Haley announced her shock resignation in October, after holding the post for 18 months.
Haley similarly had little foreign policy experience when appointed, although she had a national name as the governor of SC.
President Donald Trump confirmed he will nominate former Attorney General William Barr to lead the Justice Department again, telling reporters Friday that Barr was "my first choice since Day One".
"It will have to do with the Joint Chiefs of Staff, and succession", Mr. Trump said.
Asked about Israel's plans to demolish the Palestinian village of Khan al-Ahmar, in spite of protests from the European Union and United States lawmakers, Nauert framed the issue as an Israeli legal matter, referring the reporter who posed the question to the Israeli government.
It's likely that she'll also be asked to answer for the Trump administration's scorn for worldwide bodies, including the UN, Bloomberg News reported.
A White House official says the Trump administration is downgrading the US diplomatic post at the United Nations to a non-Cabinet position.
Nauert would replace Nikki Haley, who is resigning at the end of the year.
That means Nauert would wield less clout than her predecessor, both at the United Nations and within the administration, and as a result, would pose nowhere near the challenge to national security adviser John Bolton, White House chief of staff John Kelly or Pompeo.
Haley, in what could be a final diplomatic push, on Thursday failed in a bid for the UN General Assembly to condemn the Palestinian Hamas movement for firing rockets at Israel. If her much more recent experience at the State Department provides such rich fodder for critics, it portends a hard confirmation process ahead.
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.
While Nauert must still be confirmed by the US Senate, Benjamin said she will easily get the approval of the Republican-controlled chamber.
He said United States influence is at a "low ebb", partly because of the absence of empowered ambassadors under Trump.
Haley is a powerful presence in the administration and won Cabinet-level status despite officially reporting to Secretary of State Mike Pompeo.