Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. House Impeachment Panels Ask Key Trump Aide Mulvaney to Testify Ken Bredemeier WASHINGTON - U.S. House of Representatives committees leading the impeachment inquiry targeting President Donald Trump said Tuesday they want to question acting White House chief of staff Mick Mulvaney about his knowledge of Trump's efforts to press Ukraine to open investigations to help him politically. The House Foreign Affairs, Intelligence and Oversight panels said they asked Mulvaney to testify on Friday, although it was not immediately clear whether he would appear for closed-door questioning at the Capitol. Trump has sought, with some success, to block key aides from testifying about his actions involving the eastern European country, although other diplomatic and national security officials have answered the impeachment investigators' questions. "Based on evidence gathered in the impeachment inquiry and public reporting," the committees told Mulvaney in a letter, "we believe that you possess substantial first-hand knowledge and information relevant to the House's impeachment inquiry." .