US President-elect Donald Trump’s pick for the next secretary of state has voiced the incoming administration’s strongest backing yet for the Aukus security pact, likely reassuring Australian officials who have been privately concerned at its commitment to the deal.

Wednesday’s hearings also include Sean Duffy for the Transportation Department, John Ratcliffe for the CIA, Chris Wright for the Energy Department, and Russell Vought for the Office of Management and Budget.

Marco Rubio drew bipartisan support among Senate Foreign Relations Committee members at Wednesday's hearing and appears headed for confirmation under President-elect Donald Trump's administration.