U.S. President-elect Joe Biden has chosen retired General Lloyd Austin, an African-American who oversaw U.S. forces in the Middle East under President Barack Obama, to be his defense secretary.

Austin 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 female defense secretary.

The news was first reported by Politico.

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.

The nomination of Austin, who headed U.S. Central Command under Obama, could draw fire from some progressive groups given his role in retirement on the board of a number of companies, including weapons maker Raytheon Technologies Corp.

But Biden and Austin developed a working relationship during the Obama administration and the retired general has been advising the transition team on national security issues, one of the people familiar with the decision to name him said.

Biden’s decision to nominate the first Black defense secretary in Austin helps him make good on his diversity promise.

It also will resonate among proponents for greater diversity in the leadership of the U.S. armed forces, which is regularly criticised for failing to promote Black servicemembers and whose top tier has been largely white.

Austin has not cultivated a public persona and is not seen as someone who enjoys the media spotlight.

However, he is known to be a shrewd military strategist with deep knowledge of the U.S. armed forces.

Earlier on Monday, the Democrat who leads the House Armed Services Committee, Rep. Adam Smith, had openly shown his preference for Flournoy.

“I think Michelle Flournoy is hands-down the best-qualified person to do the job,” Smith said.

But David Segal, executive director of the progressive group Demand Progress, said Austin was a better choice given his role presiding over drawdowns of forces from Iraq and Afghanistan.

And while he had some concerning ties to major companies like Raytheon, they were not as broad in scope as those of Flournoy.

“He doesn’t seem to have a web of entanglements that are as opaque and dense as hers,” Segal told Reuters.

Biden, a Democrat, has pressed ahead with the transition to the White House even as Trump, a Republican, refuses to concede the Nov. 3 election and wages a foundering effort to overturn the results with unsubstantiated claims of fraud.

Dozens of Trump’s legal challenges have been rejected by the courts, the latest on Monday when judges in Detroit and Atlanta tossed bids to decertify Biden’s election victories in Michigan and Georgia.

Biden won Michigan by about 154,000 votes and Georgia by about 12,000 votes.

In Georgia, Secretary of State Brad Raffensperger on Monday certified the state’s results, a statement said, after a third count confirmed Biden’s win.

The Electoral College will formalise results nationwide on Dec. 14.

Raffensperger, a Republican, said continued debunked claims about voting fraud were “hurting our state.”

Runoff elections for Georgia’s two U.S. Senate seats, scheduled for Jan. 5, will determine which party controls the chamber.