Biden set to pick first black defence secretary

General Lloyd J Austin is set to be appointed the black secretary of defence in the US (Pablo Martinez/AP)

President-elect Joe Biden is poised to nominate retired four-star army general Lloyd J Austin to be secretary of defence, making him the first black leader of the Pentagon.

Sources say Mr Biden has selected Gen Austin over long-time front-running candidate Michele Flournoy, a former senior Pentagon official and Biden supporter who would have been the first woman to serve in the role.