Trump transition live updates: Not yet known if Gaetz will be confirmed, Thune says

President-elect Donald Trump is moving quickly to install loyalists and allies into his administration. But he's struggling with making a decision on one of his top law enforcement positions: attorney general, multiple sources told ABC News.

Trump interviewed multiple candidates for attorney general on Tuesday, but he came away unsatisfied, sources with knowledge of the conversations told ABC News.

Trump interviewed Missouri Attorney General Andrew Bailey on Monday, and sat down with lawyers Jay Clayton and Bob Giuffra about the post, sources said. No final decision has been made, sources said.

Notably, billionaire Elon Musk has been involved in -- and sitting in on -- interviews with potential attorney general candidates, the sources said.

In a sign of how quickly other positions are moving, Pete Hegseth -- the Fox News host selected as the nominee for Defense Secretary -- was just called Monday and interviewed for the position Tuesday, a source familiar told ABC News.

Within hours, Trump made his choice, sources added. Several Republicans on Capitol Hill and even some Trump allies described being "caught off guard" by the pick.

-Katherine Faulders, Will Steakin, Rachel Scott, John Santucci

Democratic Govs. J.B. Pritzker of Illinois and Jared Polis of Colorado will be the co-chairs of a new "non-partisan" coalition of the nation's governors committed to protecting the "state-level institutions of democracy" ahead of Donald Trump's incoming presidency.

Governors Safeguarding Democracy, or GSD, will be overseen by governors and supported by a network of senior staff designated by each leader while being supported by GovAct, an organization "championing fundamental freedoms."

GovAct is advised by a bipartisan board that includes former Republican and Democratic governors and senior officials like former GOP Gov. Arne Carlson of Minnesota, former Democratic Gov. Deval Patrick of Massachusetts and former GOP Gov. Bill Weld of Massachusetts.

-ABC News’ Isabella Murray

Trump confirmed he has picked South Dakota Gov. Kristi Noem to be his Homeland Security secretary.

Trump said in a statement that Noem will work closely with "border czar" Tom Homan and "will guarantee that our American Homeland is secure from our adversaries."

The role requires Senate confirmation.

Trump has announced that billionaire Elon Musk and Vivek Ramaswamy, a former presidential candidate and ally of the president-elect, will lead a new Department of Government Efficiency.

"Together, these two wonderful Americans will pave the way for my Administration to dismantle Government Bureaucracy, slash excess regulations, cut wasteful expenditures, and restructure Federal Agencies," Trump said in a statement.

The Department of Government Efficiency is not a new government agency. Trump said it will "provide advice and guidance from outside of government" and "partner" with the White House and Office of Management and Budget to drive structural government reform.

Trump has previously said Musk would take a role in his administration as head of a new "government efficiency commission."