President Donald Trump's personal attorney Rudy Giuliani directly challenged former national security adviser John Bolton's claims that Mr. Trump tied the hold on military aid for Ukraine to an investigation of the president's political rivals. Calling the former administration official "a backstabber," he said Bolton did not come to him with any concern about the investigation into former Vice President Joe Biden and his son.

Giuliani said he investigated, on the president's behalf, corruption allegations which included the former vice president and his son Hunter, who sat on the board of a Ukrainan energy company. But so far, there is no evidence of criminal wrongdoing by either Biden.

If Bolton had issues with his work, Giuliani told CBS News correspondent Catherine Herridge that he did not complain to him.

"He never said to me, 'I've got a problem with what you are doing in Ukraine.' Never once, never winked, never sent me a little note," Giuliani said. "That's classic backstabber. So I feel I got a swamp character here. I find his testimony about the president pretty close to incredible."

But during congressional testimony in November, Fiona Hill, a former White House aide, said Bolton did complain to colleagues over Giuliani's work, as well as efforts to force out the then-U.S. ambassador to Ukraine Marie Yovanovitch. Hill said Bolton compared Giuliani to "a hand grenade that was going to blow everyone up."

In response, Giuliani said, "If he came up to me and said, 'Rudy, you're a grenade that'll blow up,' and he shows his face, I would say, 'I would never have the opportunity, 'cause you're an atomic bomb.'"

Asked if Bolton should testify at the Senate impeachment trial if he's called as a witness, as Democrats have called for, Giuliani said he shouldn't "if the president feels that it is executive privileged material."



Giuliani said he first found out about the hold on aid to Ukraine from the media and said the president did not tie the aid to an investigation of the Bidens in any of their conversations.



"Never ever discussed military aid with the president, with regard to Ukraine," he said.

EXCLUSIVE: In a wide-ranging conversation with @CBS_Herridge, @RudyGiuliani claims he's willing to testify in the Senate impeachment trial if Pres. Trump waives attorney-client privilege. https://t.co/EW6S4PFAZd pic.twitter.com/6vdzKvm6BW — CBS This Morning (@CBSThisMorning) January 29, 2020

Giuliani is notably absent from the legal team defending Mr. Trump at the impeachment trial. The White House legal team called Giuliani a "minor player" and "shiny object designed to distract."

But Giuliani said he is still the president's personal attorney and he still maintains contact with him.

Asked why he wasn't a part of the White House defense team, he said, "Well, I am, but I can't participate in what goes on in the Congress, because I'm a possible witness."

Giuliani added that he's ready to testify in the trial if he gets clearance from the White House.

