Perry's departure was announced by U.S. President Donald Trump on Thursday. He has found himself engulfed in Congress' impeachment investigation into whether the Republican president improperly withheld nearly $400 million in military aid for Ukraine in exchange for Kiev investigating his Democratic political rivals.
"It has absolutely nothing to do with Ukraine," Perry said of his planned departure in a Fox News interview, adding he was looking to return to Texas for "the next adventure in life."
Last week, the three Democratic-led U.S. House of Representatives committees leading the impeachment probe issued a subpoena for Perry to turn over documents by Friday regarding any role he played in Trump's alleged bid to pressure Ukraine.
Asked if he would meet House Democrats' deadline, Perry deferred to his legal team.
"Our general counsel is taking a look at that right now and when they send their answer at the end of the day, whatever their decision will be, I'll follow that," Perry said.
The impeachment probe centers on Trump's alleged efforts to pressure Ukraine President Volodymyr Zelenskiy in a July 25 call to investigate his unsubstantiated allegation that former Vice President Joe Biden, a leading contender for the 2020 Democratic presidential nomination, improperly tried to aid his son Hunter's business interests in Ukraine.
Trump also asked Zelenskiy for "a favor" to look into a debunked conspiracy theory about the 2016 U.S. election involving a Democratic National Committee computer server and the cybersecurity firm CrowdStrike.
Perry told Fox he had pushed Trump to make the July call, agreeing with a characterization the president had made earlier.
Perry said he urged Trump to talk in the call about corruption and providing Ukraine an alternative to natural gas from Russia, in the form of shipments of U.S. liquefied natural gas. Biden never came up in any discussions Perry had with Zelenskiy or the White House, he said.
Perry also said he had no problems about being told to consult with Trump's personal lawyer, Rudy Giuliani, on Ukraine matters. "I’ve worked with him. I trust him," Perry said. When Perry was governor of Texas, he added, "I used people outside of government all the time to give me information."