Washington CNN  — 

President Donald Trump offered then-Homeland Security secretary John Kelly the position of FBI director one day after he fired James Comey in 2017, but demanded that he be loyal, according to an Axios report citing New York Times reporter Michael Schmidt’s forthcoming book.

Trump, Schmidt writes according to Axios, said, “Kelly needed to be loyal to him, and only him.”

Kelly, who went on to serve as White House chief of staff, “immediately realized the problem with Trump’s request for loyalty, and he pushed back on the President’s demand,” Schmidt’s book states, according to Axios.

Instead, Kelly said that he would be “loyal to the Constitution and the rule of law, but he refused to pledge his loyalty to Trump.”

CNN subsequently obtained a copy of Schmidt’s book.

The job offer’s condition of loyalty helps to explain Trump’s thinking when he became just the second president in US history to fire his FBI director when he dismissed Comey in May 2017.

At the time, Comey was leading the investigation into whether Trump campaign members colluded with Russians who hacked the 2016 election. The Trump administration said it was getting rid of Comey because of the way he handled the Hillary Clinton email probe.

Comey’s firing set off a frantic scramble that ultimately led the Justice Department to appoint former FBI Director Robert Mueller as special counsel to oversee the federal investigation into Russian interference in the 2016 election, including potential collusion between Trump’s campaign associates and Russian officials.

Mueller documented extensive evidence in his final report in March 2019 that Trump tried to obstruct the Russia investigation in multiple ways, and declined to make a charging decision. A Justice Department policy said that a sitting president could not be indicted.

According to Axios, Schmidt writes that “throughout Kelly’s time working directly with Trump, Kelly was repeatedly struck by how Trump failed to understand how those who worked for him — like Kelly and other top former generals — had interest in being loyal not to him, but to the institutions of American democracy.”