Paul O'Neill, the blunt-spoken former head of Alcoa Corp who was fired after two rocky years as US President George W. Bush's Treasury Secretary, died on Saturday at the age of 84 at his home in Pittsburgh, the Wall Street Journal reported.

His family said he had been treated for lung cancer and his death was unrelated to the novel coronavirus, the WSJ reported.

O'Neill served as the Republican Bush's first Treasury Secretary, from January 2001 to December 2002, during a period of in-fighting within the administration and tough economic times worsened by the Sept. 11, 2001, attacks on the United States.

The multimillionaire former corporate chieftain - he led aluminum company Alcoa from 1987 to 2000 - was not a big fan of Bush's first round of tax cuts.

O'Neill and his wife, Nancy, had four children.