(CNN) Former Secretary of State Condoleezza Rice says she has confidence in special counsel Robert Mueller and believes "nobody should try to impede" his investigation into Russian interference in the 2016 election.

"He is a terrific person, straight shooter," Rice said of Mueller in a wide-ranging conversation with David Axelrod on "The Axe Files," which aired at 7 ET Saturday night. "I think he'll -- he will push to a conclusion. I don't have any idea what it will be. I hope, frankly, it's over pretty soon, because we need to get on with our business."

When asked about Trump's characterization of the Russia probe as a hoax, Rice said: "Well, the President shouldn't call it a hoax. Let's just say that. But the fact is we will get to the bottom of what happened. I hope that there are people spending as much time trying to figure out exactly how the Russians did what they did."

Asked if it would be a mistake for Trump to fire Mueller or to try to impede the investigation, Rice said: "I'm not going to try to give advice, and nobody should try to impede the investigation."

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