Washington CNN  — 

Energy Secretary Rick Perry is preparing for his exit from the Trump Cabinet with his name squarely in the middle of the Ukrainian controversy, raising the prospect that a once largely clean tenure could be clouded at the very end.

The controversy stems from a whistleblower’s recent allegations that President Donald Trump asked Ukrainian President Volodymyr Zelensky earlier this year to investigate 2020 presidential candidate Joe Biden and his family, and that the White House attempted to cover up the conversation.

Perry was one of what one official called the “three amigos” leading US relations with the country, meeting at least three times with Zelensky.

In an interview with CBN News on Friday, Perry said, “as God is my witness,” that neither Joe and Hunter Biden’s name came up.

“I never heard, and I talked to the President about this, I had a conversation with - a phone call - with Rudy Guiliani about it. I’ve talked to the previous ambassador. I’ve talked to the current ambassador. I’ve talked to Kurt Volker, Gordan Sondland, the EU ambassador – every name that you’ve seen out in the media and not once, not once as God as my witness, not once was a Biden name – not the former vice president, not his son ever mentioned.”

He added: “Corruption was talked about in the country but it was always a relatively vague term of, you know, the oligarchs and this and that and what have you.”

Perry is also is scheduled to meet with Ukrainian officials this coming week “to develop enhanced interconnections between Poland and Ukraine,” the department announced Friday.

The department’s limited statements about what was discussed in Perry’s Ukraine meetings focus on energy policy. One also notes that Zelensky “articulated his administration’s commitment to defeating corruption and pledged to launch much anticipated reforms.”

In an interview this summer, Sondland, the US ambassador to the European Union, called Perry one of the “three amigos” on Ukraine.

“We have what are called the three amigos, and the three amigos are Secretary Perry, Ambassador Volker and myself,” Sondland said. The three have “been tasked with sort of overseeing the Ukraine-US relationship between our contacts at the highest levels of the US government, and now the highest levels of the Ukrainian government.”

The top Democrat on the Foreign Relations Committee, Sen. Bob Menendez, asked Perry about several of those conversations and whether he has any knowledge of the highly classified White House system where, the whistleblower alleged, White House officials tried to bury notes of the Trump-Zelensky call.

Perry’s spokeswoman, Shaylyn Hynes, said in response to the request that the “Department is always willing to work with Congress in response to requests that follow proper procedures,” but did not specify whether the department believes Menendez’s request is “proper.” Menendez requested a reply from Perry by Friday.

Perry turned to humor this week when asked why he was tapped to replace Vice President Mike Pence on one of the trips to meet with Zelensky.

“Oh I think it’s because I’m just such a darned good Cabinet member, and very capable, and probably pretty knowledgeable about the energy industry,” he said at an energy conference.

Perry is scheduled to visit the White House on Friday, according to a source familiar with the plans. Perry posted online late Thursday that he plans to bring one of his grandchildren “to the White House tomorrow to have pic with POTUS.”

Since taking the position of energy secretary, Perry has held unusually firm footing in the high-turnover Cabinet, surviving – largely outside of the harsh DC spotlight – as scandal, infighting, and ethical lapses dragged his colleagues down.

Perry’s departure from office has been in the works for a while and is a planned succession as Perry looks to move to the private sector, a source with ties to Perry told CNN.

Hynes did not specify a timeline for Perry’s departure in a statement issued as news outlets, including Politico, reported that Perry would depart later this year.

She said the reports were based “on rumors,” and noted “he is still the Secretary of Energy and a proud member of President Trump’s cabinet. One day the media will be right. Today is not that day.”

In office, Perry has made a point of visiting and praising the work of the department’s national laboratories. He said at his confirmation hearings that he regretted calling for the department’s elimination during his 2012 presidential campaign.

This story has been updated with quotes from Perry’s interview with CBN News.

CNN’s Pamela Brown, Ross Levitt, Kylie Atwood and Dan Berman contributed to this report.