President Trump's private attorney, former New York City Mayor Rudy Giuliani (R), said Monday on "The Story" that the "truth is relative" to prosecutors on Robert Mueller's probe of the president.

Giuliani was responding to criticism of his interview with NBC News' Chuck Todd, in which he said the "truth isn't truth" when it comes to whether Trump could walk into a perjury trap if interviewed by Mueller.

Giuliani said that a key question Mueller's team would ask Trump is whether he told then-FBI Director James Comey to slacken his investigation of ex-National Security Adviser Michael Flynn.

"It's like a tree falling in a forest. How do we know what the truth is?" Giuliani said, adding that he would believe Trump's account and Mueller would likely believe Comey.

"They'd probably charge him with perjury," he said. "To prosecutors in this case, truth is relative."

Giuliani said that Todd was combative in his interview, constantly interrupting the mayor to tout "talking points" against Trump's case.

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He said Todd would likely believe Comey as well in that instance.

Giuliani also said Mueller's case is not progressing "expeditiously" as promised.

He said that if Mueller is trying to "do the same thing Comey did" when he made public statements about the Clinton investigation, he is "trying to be judge and jury of the 2018 elections."

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