A senior adviser to Secretary of State Mike Pompeo has resigned amid growing controversy over the State Department’s role in attempts by President Trump and his personal attorney to have Ukrainian authorities investigate Joe Biden, The Washington Post reports. Michael McKinley, Pompeo’s adviser, had been a diplomat for over 30 years and served as ambassador to Peru, Colombia, Afghanistan, and was serving as the U.S. ambassador to Brazil before he was tapped for his advising role last year. McKinley’s departure comes as Pompeo’s presence on the phone call between President Trump and Ukrainian President Volodymyr Zelensky, in which Trump asked Zelensky to investigate former Vice President Joe Biden and his son Hunter, comes under fire as the House expands their impeachment inquiry. The Post reports that McKinley’s resignation comes as many at the State Department grow frustrated with Pompeo’s perceived lack of support for department officials who are caught up in the Ukraine investigation. Pompeo is expected to formally announce McKinsey’s departure Friday.