President-elect Joe Biden has chosen retired General Lloyd Austin, who oversaw U.S. forces in the Middle East under President Barack Obama, to be his defense secretary, two people familiar with the decision said on Monday.

Austin, who would be the first Black U.S. secretary of defense, was a surprise pick over Michele Flournoy, a former top Defense Department official who was considered the leading contender for the job. Flournoy would have been the first woman defense secretary.

Austin, who retired in 2016, will need a waiver from Congress since it has been less than the required seven years since he served. He would be the second Pentagon chief in four years to need a waiver, after President Donald Trump picked James Mattis, a retired Marine general, to be his first defense secretary.

Biden, who takes office on Jan. 20, on Monday also announced key members of his health team to lead the administration’s response to the raging coronavirus pandemic.

Biden chose California Attorney General Xavier Becerra for secretary of health and human services and Dr. Rochelle Walensky, chief of infectious diseases at Massachusetts General Hospital in Boston, to run the U.S. Centers for Disease Control and Prevention (CDC).