Pete Hegseth, President-elect Donald Trump's choice to lead the U.S. Department of Defense, told U.S. lawmakers Tuesday he would bring back accountability and "a warrior ethos" to the nation's military.

In the first confirmation hearing in the U.S. Senate for Trump's Cabinet secretary picks, Hegseth faced criticism from Senate Democrats over his statements about women and transgender people serving in the military, as well as allegations of sexual assault, drunkenness and financial mismanagement of two nonprofits serving U.S. veterans that he led.

Trump Cabinet choice faces tough first day of questions on Capitol Hill

"This nomination is unconventional. The nominee is unconventional, just like that New York developer who rode down the escalator in 2015 to announce his candidacy for president," Senate Armed Services Chairman Roger Wicker, a Republican, said Tuesday.

Trump Cabinet choice faces tough first day of questions on Capitol Hill

"Mr. Hegseth will bring energy and fresh ideas to shake up the bureaucracy. He will focus relentlessly on the war fighter and the military's core missions, deterring wars and winning the ones we must fight," Wicker continued.

Trump Cabinet choice faces tough first day of questions on Capitol Hill

Hegseth, a former television host at the conservative Fox News channel, also served as an officer in the Army National Guard in Iraq, Afghanistan and Guantanamo Bay and is the author of several books.

"I don't have a similar biography to defense secretaries of the last 30 years," Hegseth told senators in his opening statement. "But as President Trump also told me, we've repeatedly placed people atop the Pentagon with the supposed right credentials, whether they are retired generals, academics or defense contractor executives. And where has it gotten us?"

Hegseth said his priorities, if he is confirmed as secretary of defense, would focus on the threat posed by China and defense of the homeland while reorienting the United States away from entanglements in the Middle East. He also pledged to restore morale and end diversity initiatives that he sees as harmful to establishing a merit-based military.

"Getting anything that doesn't contribute to our democracy out of how decisions are made inside the Pentagon," Hegseth said of the ways he sees his potential role. "What gender you are, what race you are, your views on climate change, your conscience and your faith should have no bearing on whether you get promoted, or whether you're selected to go to West Point, or where you go to school. Only thing that should matter is how capable are you at your job. How excellent are you at your job."

If confirmed, Hegseth would be the first secretary of defense to have served as a junior officer on the front lines and the first secretary from the generation that fought in post-9/11 wars.

Senate Democrats said Hegseth's experience running two nonprofits benefiting military veterans with fewer than 100 employees was not sufficient experience.

"We're hiring you to be the CEO of one of the most complex, largest organizations in the world. We're the board of directors here. I don't know of any corporate board of directors that would hire a CEO, that said, you know, I supervised 100 people before," said Democratic Senator Gary Peters.

The Department of Defense has more than 3 million service members and a budget of $857 billion.

Senator Jack Reed, the top Democrat on the committee, said that the FBI background investigation into Hegseth was “insufficient” and that there are still FBI obligations to talk to people.”

"You lack the character and composure and competence to hold the position of defense," Reed said, noting that he has voted for all nine previous nominees for secretary of defense, including nominees during Trump's first term.

All Cabinet nominees undergo a background check and an ethics review.

Hegseth faces allegations of financial mismanagement of the two nonprofits where he served as executive director: Vets for Freedom and Concerned Veterans for America.

After a 2009 audit of Vets for Freedom, Hegseth acknowledged the organization was $500,000 in debt, and he was demoted. During his time at Concerned Veterans for America, Hegseth faced whistleblower allegations of personal misconduct and financial mismanagement, which resulted in an investigation and a report.

Hegseth said the allegations were part of a coordinated smear campaign by left-wing media and largely came from anonymous sources.