Comey: Trump's attacks on the FBI make America less safe

President Donald Trump's political attacks on the FBI make America less safe because they undermine public confidence that the bureau is an "honest, competent and independent" institution, fired director James Comey told The Associated Press today.

In a telephone interview, Comey also said it was logical that special counsel Robert Mueller would seek to interview Trump since the president is a subject of an investigation into Russian meddling in the 2016 presidential election.

Comey ruled out seeking elected office and said that, as a leader, he took responsibility for some of the turmoil that has surrounded the FBI in recent months.

The ex-FBI chief said it was clear the president's blistering attacks on the bureau, including Trump's calls for scrutiny of his political opponents and his suggestion that Comey should be jailed, affect public safety in "hundreds and thousands of ways" especially if crime victims no longer believe that an agent knocking on their door will help them or that an agent testifying before a jury can be believed.

"To the extent there's been a marginal decrease in their credibility at that doorway, in that courtroom and in thousands of other ways, their effectiveness is hit. So it's hard," Comey said.

"You're not going to be able to see it, but logic tells me that it's there, which is why it's so important that we knock it off as a political culture." Trump fired Comey last May, an act now under investigation by Mueller for possible obstruction of justice.

The White House initially said Trump had fired him over his handling of the Hillary Clinton email case, but the president later said he was thinking of "this Russia thing" when he made the move.

Comey is now promoting his new book, "A Higher Loyalty," and has given a series of interviews in which he has described his interactions with the president and characterised him as morally unfit for office.

But his departure from the bureau has also been followed by a cascade of negative headlines that seem to have given ammunition to critics of the FBI, including Trump.