Washington (CNN) Mike Pompeo, the Trump administration's nominee to lead the State Department, told senators on the Foreign Relations committee on Thursday he has cooperated with special counsel Robert Mueller's Russia investigation.

"I spoke with special counsel Mueller, who interviewed me, requested an interview, I cooperated," he told the committee's top Democrat Sen. Bob Menendez, who asked about the investigation, during his confirmation hearing.

He also said President Donald Trump has never asked him do anything "improper" as it relates to the Russia probe during then-FBI Director James Comey's time as FBI director, but he declined to say if the President asked him to do anything about the Comey probe and could not "recall" the nature of a March 2017 conversation where Trump reportedly asked Pompeo to get Comey to pull back.

"I am not going to talk about private conversations I've had with the President," he said.

In his opening remarks, Pompeo said the Trump administration considers Russia a "danger to our country" and that years of a "soft policy" toward Russian aggression are "now over."

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