DUBAI, United Arab Emirates (AP) — Outgoing U.S. Energy Secretary Rick Perry says he asked President Donald Trump to make the phone call at the center of the impeachment inquiry because it was "important."

Speaking to reporters in Dubai on Saturday, Perry says he urged Trump to call Ukrainian President Volodymyr Zelenskiy for professional reasons and it had nothing to do with former Vice President Joe Biden or his son Hunter. Perry tells the Associated Press he never heard the word Burisma, a Ukrainian gas company that once employed Biden's son.

The impeachment inquiry is investigating whether Trump was withholding military aid unless Zelenskiy went public with a promise to investigate them.

Perry has been subpoenaed for his involvement in the call but says he won't cooperate with a process he calls "not only illegal but improper."