U.S. Treasury Secretary Paul O'Neill sits in his office September 19, 2001 in Washington, DC. Sworn in to his position January 20, 2001, he was fired in December 2002.

Paul O'Neill, the blunt-spoken former head of Alcoa Corp who was fired after two rocky years as U.S. 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. He then argued in vain with others in the administration, including Vice President Dick Cheney, against more cuts that he felt could fuel budget deficits and hurt the economy.

He also earned a reputation as a loose cannon as Treasury secretary with comments that at various times infuriated members of Bush's inner circle, fellow Republicans in Congress, Wall Street, Latin American governments and others.

It was Cheney, his friend dating to the 1970s in President Gerald Ford's administration and had recruited O'Neill into the Treasury job, who told him that he was fired. O'Neill said Cheney had asked him to say his departure was his own decision, but O'Neill refused.

"I'm too old to begin telling lies now," he said.

History bore out his concerns over the Bush tax cuts, which along with the costs of Bush's wars in Iraq and Afghanistan contributed to soaring U.S. budget deficits in subsequent years.

Regarding Iraq, O'Neill said Bush's team had decided on a course of war which it then tried to justify by touting the threat posed by Iraqi leader Saddam Hussein's weapons of mass destruction. After the invasion, no such weapons were found.