Washington (CNN) Energy Secretary Rick Perry, who has met on at least three occasions with Ukrainian President Volodymyr Zelensky, on Wednesday pledged to work with lawmakers looking into a whistleblower's allegations about President Donald Trump's communications with Zelensky.

"I'll just briefly say we're going to work with Congress and answer all their questions," Perry said at a department event on artificial intelligence and energy.

Perry has met with Zelensky at least three times while in office, including when replaced Vice President Mike Pence in leading a US delegation to Zelensky's inauguration last spring.

On Tuesday, Sen. Bob Menendez of New Jersey, the top Democrat on the Foreign Relations committee, sent a letter questioning Perry about that trip as well as his second meeting with Zelensky, a June 2019 dinner.

Energy Department spokeswoman Shaylyn Hynes told CNN, "Regardless of subject, the Department is always willing to work with Congress in response to requests that follow proper procedures."

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