(CNN) Former FBI director James Comey said on Wednesday that he does not have a nickname for President Donald Trump, calling him only "the President of the United States" out of respect for the office.

Comey was asked during a town hall on Wednesday hosted by CNN's Anderson Cooper what his nickname for the President is given that Trump has quite a few nicknames for him.

"I don't have a nickname for him," Comey said. "Honestly, I call him the President of the United States because I respect the office."

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Trump has previously called Comey, "Slippery James Comey,"an "untruthful slime ball" and a "LEAKER & LIAR."

Comey went on to say, "no matter my concerns about him, I want him to be successful. ... We should root for our President. That also doesn't mean we should fail to hold him accountable."