U.S. President-elect Joe Biden on Tuesday announced that he plans to nominate retired Army Gen. Lloyd Austin to head the Pentagon, making him the first African American to serve in the post if he is confirmed by the Senate.

Calling Austin a "trusted and crisis-tested leader" who has served as the chief architect of the effort to defeat Islamic State militants in Iraq and Syria, Biden said in a statement that he expects the retired general to help "revitalize our alliances in the face of global threats, and ensure the safety and security of the American people."

Combined photo shows (from L) Lloyd Austin (Getty/Kyodo), Janet Yellen (Getty/Kyodo) and Antony Blinken. (Kyodo) 

Austin retired from the Army in 2016 following more than 40 years of military service. Given that he left active duty less than seven years ago, he would need a waiver from Congress to become secretary of defense in 2021.

He was the first African American to serve as commander of U.S. Central Command, which is responsible for defending the country's interests in the Middle East and Central and South Asia.

Biden, the 78-year-old former vice president under Barack Obama, has vowed to form a diverse administration that represents the multicultural nature of the United States.

Having already nominated two white officials for top posts -- Antony Blinken for secretary of state and Janet Yellen for treasury secretary -- Biden has reportedly been under pressure to pick a black nominee for defense secretary, another prominent post within the Cabinet.

Biden, along with Vice President-elect Kamala Harris, the first female, first black and first Asian American to serve in the second-highest U.S. office, will be sworn in on Jan. 20 following their victory in the Nov. 3 presidential election.

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