Retired U.S. Army Gen. Lloyd Austin on Friday took over as the first black Pentagon chief shortly after being confirmed 93-2 by the Senate.
Austin was greeted outside the Pentagon with an elbow bump by Chairman of the Joint Chiefs of Staff Gen. Mark Milley before heading inside to be sworn in and begin his first day as defense secretary, leading a military that is now nearly 17 percent African American.
"I look forward to working with you, see you around campus," Austin said to reporters, ignoring questions.
After being confirmed by the Senate, Austin was administratively sworn by Tom Muir, acting director of the Washington Headquarters Services.
Earlier in the day, President Joe Biden signed a waiver approved by Congress allowing Austin to take the job even though it's been fewer than seven years since he retired in 2016.
The rule for former military leaders taking over at the Pentagon was instituted to address concerns about keeping civilian control of the military and worries someone recently retired might be too wedded to policies and to people he or she worked with during their time in the military.
A similar waiver was granted in 2017 for President Donald Trump's first defense secretary, retired U.S. Marine Gen. Jim Mattis.
"If you confirm me, I am prepared to serve now -- as a civilian -- fully acknowledging the importance of this distinction," Austin said at his Jan. 19 confirmation hearing before the Senate Armed Services Committee.
"I understand and respect the reservations some of you have expressed about having another recently retired general at the head of the Department of Defense," he said. "The safety and security of our democracy demands competent civilian control of our armed forces, the subordination of military power to the civil."
He pledged to surround himself with experienced civilians whom he said he would empower to "enable healthy civil-military relations, grounded in meaningful oversight."
On Friday afternoon, Austin sent out a day-one message to the force.
"The way I see it, my job as Secretary of Defense is to make you more effective at doing yours. That means ensuring you have the tools, technology, weapons, and training to deter and defeat our enemies. It means establishing sound policy and strategy and assigning you clear missions. It means putting a premium on cooperation with our allies and partners. And it means living up to our core values, the same ones our fellow citizens expect of us," Austin said in he written message.
Austin said he planned to include the under secretary of defense for policy in top decision-making meetings "ensuring strategic and operational decisions are informed by policy."
He said his first major challenge would be dealing with the coronavirus pandemic, and said that if confirmed he will quickly review the Pentagon's contributions to the nationwide distribution of vaccines.
Another top priority, Austin said, would be to ensure Defense Department employees have "a working environment free of discrimination, hate and harassment."
"If confirmed, I will fight hard to stamp out sexual assault, to rid our ranks of racists and extremists, and to create a climate where everyone fit and willing has the opportunity to serve this country with dignity," said Austin. The job of the Department of Defense is to keep America safe from our enemies. But we can’t do that if some of those enemies lie within our own ranks."
The former commander of U.S. Central Command -- with jurisdiction over military activities in the Middle East -- Austin retired after more than 40 years of military service, including a stint leading U.S. forces in Iraq and the campaign against the Islamic State.
A native of Mobile, Alabama, the 67-year-old Austin finished his career in 2016 as the commander of U.S. Central Command, where he was in charge of all American troops in the Middle East.
At the White House, press secretary Jen Psaki, noting his historic confirmation, said Austin "has been breaking barriers all his life."
ABC News Luis Martinez contributed to this report.