Washington (CNN) It was early December when President Donald Trump announced he had selected State Department spokesperson Heather Nauert to replace Nikki Haley as the next US ambassador to the United Nations. Almost two months later her nomination has not been made official, no date has been set for a Senate confirmation hearing and Nauert has retreated from the public gaze.

There is no tangible growing opposition to her appointment among Republicans, but there seems to be no urgency from the White House and GOP members of Congress to get her into the job.

When you bring up Nauert's name to State Department officials many quip that they have not seen her in "ages." Though she is technically still the spokesperson for US foreign policy, her last briefing from the State Department podium was in late November and she has handed over the reins to her deputy, Robert Palladino.

Nauert, a former Fox News anchor who arrived at the State Department in 2017, was an unconventional choice for the UN job and concerns have been raised about her lack of diplomatic experience. Her supporters, however, say she spent the last two years immersed in the Trump administration's foreign policy.

Nauert is still working out of Foggy Bottom, according to sources at the State Department, and is working hard prepping for her confirmation hearing. The team around her is largely made up of the people who helped Haley prep for her own confirmation hearing, minus members of Haley's inner circle.

Nauert is also well aware, according to sources familiar with her preparation process, that Democrats will press her on what they see as her lack of foreign policy experience. They say she is prepared to flip that accusation around and argue that in many cases members of Congress don't always have the perfect backgrounds for their jobs either.

Head scratching

The delay to Nauert's nomination has led to some head scratching at the UN, in Congress and among those who watch US foreign policy. One observer said the White House should have much of the paperwork already, given that it must have run internal checks when the former Fox host was approved to be State Department spokeswoman.

The State Department has been having trouble gathering all the documents needed to thoroughly vet Nauert for the position, sources familiar with the proceedings say. That process requires checking Nauert's financial history, looking for potential conflicts of interest or any issue that might make a nominee vulnerable to foreign pressure -- part of the usual Senate scrutiny brought to bear on nominees.

The UN job is not the only senior diplomatic post that remains unfilled. At the State Department 11 top leadership roles are vacant. Nine of those jobs have nominees but no hearings scheduled.

The State Department not reply to CNN's requests for comment on the status of Nauert's nomination.

The shutdown also slowed the nomination, according to administration officials. Those familiar with the shutdown's impact on the White House note that the office of presidential personnel hit a "standstill" and that many of the White House liaisons who work with Congress were furloughed, according to Capitol Hill staffers.

When asked if sending Nauert's nomination to Congress officially would be a top priority now that the government has reopened, the White House said that all nominations would be moving forward.

"Some of the routine paperwork involving nominations was delayed during the partial government shutdown, but now that the government is open, these nominations will move forward," explained a White House official.

However, a confirmation hearing for Bill Barr, Trump's nominee for attorney general, was held during the shutdown and last week a list of ambassadorial choices and nominees for other State Department roles was officially submitted.

The fact Nauert was not on that list caused some to raise eyebrows and question if she was still Trump's pick for the job. But the majority of the officials on that list were being resubmitted, having not been confirmed by the last Congress.

The White House did not reply when asked if sending Nauert to Congress officially would be a top priority now that the government has reopened.

The Senate Foreign Relations Committee, which will host Nauert's confirmation hearing, plans to focus initial hearings on "substantive policy," not personnel, explain sources on Capitol Hill. They say the committee's new chairman, Republican Sen. James Risch of Idaho, wants to highlight China and US foreign policy more broadly. There are no signals of increasing trepidation from Republicans about Nauert, but "they are not chomping at the bit to get her through," according to one Republican aide.

'I brought up her name and got no response at all'

The committee still has to get its new membership in order and one US official indicated that members of Congress are just not focused on Nauert's appointment right now.

"I brought up her name and got no response at all," explained one government official who has been in talks with members of Congress about issues they are focused on discussing with the administration. "But when I bring up North Korea, Syria or the border or Afghanistan, I get a response."

The expectation is that Nauert will succeed in being confirmed, given that Republicans control the Senate, unless her hearing goes badly wrong.

"Republicans have generally gone along with the administration in its nominations," former US Ambassador to the UN Thomas Pickering told CNN. "Of course, if Heather does so palpably badly she is an embarrassment, then some Republicans may shift, recognizing that in this day some degree of embarrassment risks their future in politics. But that hangs on the performance during her hearing."

Angst at the UN

Secretary of State Mike Pompeo took the lead for the US during Saturday's UN Security Council meeting on Venezuela and US diplomats have told CNN that things are operating smoothly under acting Ambassador Jonathan Cohen. But the lack of political leadership has unsettled some members of the US delegation.

"It is kind of a scary, weird time," a US UN official told CNN, adding that the leadership void is creating "angst amongst staff." Though the official added that Cohen "is doing a remarkable job keeping that all at bay."

"I want to get Heather here as soon as possible. We like her," another US UN official said, noting that Nauert had garnered a positive relationship with the New York office over the last two years. "But Nikki had such a close relationship with Trump. Without that, we will see how effective she (Nauert) can be."

As she hunkers down, Nauert has also gone quiet online. She initially tweeted thanking Trump for his confidence in her, saying she was "humbled" by his intent to nominate her. Since then her Twitter account has almost exclusively been filled with retweets of the official accounts of the State Department deputy spokesperson, the State Department and Pompeo.

Her activity on Instagram has completely halted. Her last post, an image of her leading a mock briefing with the young daughters of US diplomats in Buenos Aires, went up just days before Trump announced his intent to nominate her.