WASHINGTON -- Impeachment investigators issued subpoenas Friday to three more Trump administration officials, demanding that they testify in the probe of U.S. President Donald Trump's efforts to force Ukraine to feed him damaging information about his Democratic political opponents.
The chairs of the three House committees leading the impeachment inquiry subpoenaed two officials of the White House Office of Management and Budget: acting director Russell Vought and Michael Duffey, who oversees national security programs.
They also subpoenaed State Department counsellor T. Ulrich Brechbuhl.
Investigators asked all three earlier this month to testify, but none have appeared.
The Trump administration has refused to make its officials available for depositions in the investigation and resisted supplying documents as well. But witnesses have been appearing anyway after they are issued subpoenas.
"The committees therefore have no choice but to issue a subpoena compelling your mandatory appearance," the letters read.
Investigators want to know why nearly $400 million in military aid to Ukraine was delayed, even though it was approved by Congress and signed into law by Trump.
Others have testified that Trump was demanding investigations of Democrats in exchange for the aid and for an Oval Office meeting coveted by Ukraine's new president, Volodymyr Zelenskiy.
