Donald Trump was expected to formally nominate his selection for secretary of defense during the latest stop on the president-elect's "thank you" tour in North Carolina Tuesday night, according to a new report. The choice of retired Marine Gen. James "Mad Dog" Mattis to lead the Pentagon has varied along party lines, which was to be expected following such a divisive campaign season and election.

Though Mattis' selection was only announced last week, Democrats were already looking to delay his eventual confirmation proceedings, Politico reported. Conversely, Republicans were looking to add a provision to the year-end spending bill that would make it easier and swifter for Mattis to be confirmed. The former general retired in 2013, but the law dictates a defense secretary must have been out of the armed services for at least seven years.

But Trump has been resolute if not methodical in choosing his closest advisers, and he doesn't seem worried about any potential backlash surrounding those picks. That was evident Monday when he appointed Dr. Ben Carson to lead the Department of Housing and Urban Development. The retired neurosurgeon had previously openly admitted he wasn't qualified to lead a government agency, something that did not deter Trump but rankled critics.

As the president-elect kept working to round out his closest advisors and leaders of the 15 executive departments, a handful of key positions remained unfilled with less than 45 days until Inauguration Day. Below is a full list of the cabinet positions that are spoken for and those still up for grabs, courtesy of the New York Times.

Appointed Cabinet Positions:

Department of Defense: James N. "Mad Dog" Mattis

Department of Treasury: Steven Mnuchin

Department of Transportation: Elaine L. Chao

Department of Health and Human Services: Tom Price

Department of Commerce: Wilbur Ross

Department of Education: Betsy DeVos

United Nations Ambassador: Nikki Haley

Department of Housing and Urban Development: Dr. Ben Carson

Central Intelligence Agency: Mike Pompeo

Attorney General: Jeff Sessions

National Security Adviser: Michael T. Flynn

Chief of Staff: Reince Priebus

Chief Strategist: Stephen K. Bannon

Unfilled Cabinet Positions:

Secretary of State

Director of National Intelligence

Department of the Interior

Department of Agriculture

Department of Labor

Department of Energy

Department of Veterans Affairs

Department of Homeland Security

Environmental Protection Agency

U.S. Trade Representative