Nov. 16 (UPI) -- Mark Sandy, a senior Office of Management and Budget official, arrived Saturday on Capitol Hill to testify in the House's impeachment inquiry in defiance of White House orders.
Speaking during a closed-door meeting, he's the first official from the office to give testimony to lawmakers in the probe.
The agency itself has rejected repeated subpoenas for documents related to House Democrats' investigation into whether the Trump administration withheld military aid to Ukraine to pressure the country to launch an investigation of Democratic presidential candidate Joe Biden, and his son, Hunter Biden, for political gain.
Investigators hope Sandy has insight on internal conversations he can share surrounding the Trump administration's freezing of nearly $400 million in aid to Ukraine over the summer.
On the July 25 call, Trump asked Zelensky to "do us a favor" and look into Biden and his son, and suggested he also check if Ukraine was involved in 2016 election interference despite special counsel Robert Mueller concluding Russia was the country involved.
House Speaker Nancy Pelosi announced the formal impeachment inquiry in September after Trump released a rough, declassified transcript of the July 25.
William Taylor, the top U.S. diplomat in Ukraine who testified in the impeachment inquiry Wednesday, said the day after the July 25 phone call, he learned the details of a separate phone call between Trump and U.S. Ambassador to the European Union Gordon Sondland from a staffer. He said his staffer told him that Sondland told him that Trump cares more about investigating the Bidens than he does about Ukraine foreign policy.
"I and others sat in astonishment," Taylor said. "Ukrainians were fighting Russians and counted on not only the training and weapons but also the assurance and U.S. support."
OMB Director Mick Mulvaney, who is also acting chief of staff, said the aid was withheld to pressure Ukraine to investigate unsubstantiated theories about Ukrainian interference in the 2016 election in a press conference last month, but shortly after denied the remarks.