“Past Democrat and Republican administrations would not be inclined to permit senior advisers to the president to participate in such a ridiculous, partisan, illegitimate proceeding — and neither is this one.” Gidley said.
Mark Sandy, director of national security programs at the Office of Management and Budget, was also scheduled to appear Friday morning. While his plans were unclear, other OMB officials have ignored subpoenas. Mulvaney is also director of the OMB.
Last month, Mulvaney told reporters in the White House briefing room that President Donald Trump had held up U.S. military assistance to Ukraine in order to get it to investigate a conspiracy theory involving Ukraine influencing the 2016 presidential election.
"The look back to what happened in 2016 certainly was part of the thing he was worried about in corruption with that nation, and that is absolutely appropriate," Mulvaney said.
ABC’s Jonathan Karl pressed Mulvaney: "To be clear: what you just described is a quid pro quo. It is 'funding will not flow unless the investigation into the Democratic server happened, as well.'"
"We do that all the time with foreign policy," Mulvaney replied.
Later in the day, he walked those comments back, saying in a statement, "There was absolutely no quid pro quo between Ukrainian military aid and any investigation into the 2016 election.”
Out of 13 witnesses that Democrats scheduled for closed-door depositions this week, only two people ― Jennifer Williams, special adviser to Europe and Russia to Vice President Mike Pence, and another State Department employee, David Hale ― have shown up.
According to the State Department official George Kent, whose deposition transcript was released Thursday, during the July 18 videoconference in which it was announced that the aid would be held up, Kent said that an OMB official who he didn’t recognize said that Mulvaney “at the direction of the president had put a hold on all security assistance to the Ukraine.”
Meanwhile, the House committees in charge of conducting the depositions are expected to release the transcript of former White House official Fiona Hill's deposition on Friday, two sources with knowledge of the timing told NBC News. One of the sources said that Lt. Col. Alexander Vindman’s transcript is also expected to be released Friday.
White House chief of staff Mick Mulvaney announces that the G7 will be held at Trump National Doral, Thursday, Oct. 17, 2019, in Washington. (AP Photo/Evan Vucci)
WASHINGTON, DC - OCTOBER 17: Acting White House Chief of Staff Mick Mulvaney answers questions during a briefing at the White House October 17, 2019 in Washington, DC. Mulvaney answered a range of questions relating to the issues surrounding the impeachment inquiry of U.S. President Donald Trump, and other issues during the briefing. (Photo by Win McNamee/Getty Images)
Acting White House Chief of Staff Mick Mulvaney arrives to answer questions from reporters during a news briefing at the White House in Washington, U.S., October 17, 2019. REUTERS/Leah Millis
WASHINGTON, DC - SEPTEMBER 08: White House Budget Director Mick Mulvaney speaks to members of the media after a House Republican Conference meeting September 8, 2017 at the Capitol in Washington, DC. Mulvaney was on the Hill to push for the Trump Administration's Hurricane Harvey relief and debt limit package. (Photo by Alex Wong/Getty Images)
Mick Mulvaney, director of the Office of Management and Budget (OMB), holds up what he described as U.S. President Barack Obama regulations during a White House press briefing in Washington, D.C., U.S., on Thursday, July 20, 2017. Mulvaney has called Trump's tax-cutting approach to the economy MAGAnomics, a spin on Trump's campaign slogan, 'Make America Great Again' and has repeatedly attacked the Congressional Budget Office (CBO) for its estimates on the impact of Republicans' plans to repeal and replace Obamacare. Photographer: Andrew Harrer/Bloomberg via Getty Images
Mick Mulvaney, Director of the Office of Management and Budget, speaks about 'MAGAnomics' during the daily press briefing in the Brady Press Briefing Room at the White House in Washington, DC, July 20, 2017. / AFP PHOTO / SAUL LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images)
WASHINGTON, DC - JUNE 21: OMB Director Mick Mulvaney testifies during a Financial Services and General Government Subcommittee hearing on the budget for the Office of Management and Budget on Capitol Hill on June 21, 2017 in Washington, DC. (Photo by Astrid Riecken/Getty Images)
WASHINGTON, DC - Budget Director for President Donald Trump, Mick Mulvaney explains and defends the administration's 2018 budget to the House Budget Committee on Capitol Hill in Washington, DC Wednesday May 24, 2017. (Photo by Melina Mara/The Washington Post via Getty Images)
UNITED STATES - MAY 24: OMB Director Mick Mulvaney testifies before a House Budget Committee hearing in Longworth Building titled 'The President's FY2018 Budget' on May 24, 2017. (Photo By Tom Williams/CQ Roll Call)
Mick Mulvaney, director of the U.S. Office of Management and Budget (OMB), listens during a House Budget Committee hearing on U.S. President Donald Trump's fiscal 2018 budget proposal in Washington, D.C., U.S., on Wednesday, May 24, 2017. Trump would dramatically reduce the U.S. government's role in society with $3.6 trillion in spending cuts over the next 10 years in a budget plan that shrinks the safety net for the poor, recent college graduates and farmers. Photographer: Andrew Harrer/Bloomberg via Getty Images
WASHINGTON, DC - MAY 23: Office of Management and Budget Director Mick Mulvaney holds a news conference to discuss the Trump Administration's proposed FY2017 federal budget in the Brady Press Briefing Room at the White House May 23, 2017 in Washington, DC. Calling it a 'New Foundation for American Greatness,' the $4.1 trillion budget for would cut programs for the poor, including health care, food stamps, student loans and disability payments while offering big tax cuts for the wealthy. (Photo by Chip Somodevilla/Getty Images)
Mick Mulvaney, director of the U.S. Office of Management and Budget, center, holds a volume of the fiscal year 2018 budget while speaking with Davita Vance-Cooks, director of the Government Publishing Office (GPO), left, during a tour of the GPO production facility in Washington, D.C., U.S., on Friday, May 19, 2017. Presidentï¿½Donald Trumpï¿½will send to Congress on Tuesday a proposal for balancing the federal budget within 10 years through deep cuts to discretionary and safety net spending, according to a U.S. official. Photographer: T.J. Kirkpatrick/Bloomberg via Getty Images
WASHINGTON, DC - MAY 02: White House Press Secretary Sean Spicer (R) walks into the briefing room with OMB Director Mick Mulvaney (L) and Secretary of Homeland Security John Kelly (C), to brief the media on President Trump's budget, at the White House (Photo by Mark Wilson/Getty Images)
Mick Mulvaney, director of the Office of Management and Budget (OMB), right, speaks as Gray Davis, former governor of California, listens during the Leaders In Global Healthcare and Technology (LIGHT) conference at Stanford University in Stanford, California, U.S., on Thursday, May 11, 2017. The LIGHT conference gathers leaders from a broad cross-section of executives and top policy makers in the health-care field to discuss the latest developments, challenges and opportunities shaping the healthcare industry. Photographer: David Paul Morris/Bloomberg via Getty Images
WASHINGTON, DC - MARCH 16: Office of Management and Budget Director Mick Mulvaney arrives for a briefing in the Brady Press Briefing Room at the White House March 16, 2017 in Washington, DC. Mulvaney took questions about President Donald Trump's federal budget blueprint which was released Thursday. (Photo by Chip Somodevilla/Getty Images)
WASHINGTON, DC - MARCH 13: U.S. Health and Human Services Secretary Tom Price (L) and Office of Management and Budget Director Mick Mulvaney talk to reporters following the release of the Congressional Budget Office report on the proposed American Health Care Act outside the White House West Wing March 13, 2017 in Washington, DC. Price said 'We disagree strenuously' with the findings of the CBO report about the Republican's attempt to repeal and replace the Affordable Care Act, or Obamacare. (Photo by Chip Somodevilla/Getty Images)
US Vice President Mike Pence (R) delivers remarks before swearing in Mick Mulvaney (L) as Director of the Office of Management and Budget in Washington, DC, on February 16, 2017. / AFP / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
WASHINGTON, DC - FEBRUARY 16: U.S. Vice President Mike Pence (C) Mick Mulvaney (L), swears as new Office of Management and Budget Director, as his wife Pam Mulvaney holds a bible during a ceremony in the Eisenhower Executive Office Building on February 16, 2017 in Washington, DC.
(Photo by Mark Wilson/Getty Images)
UNITED STATES - NOVEMBER 4: Reps. Mick Mulvaney, R-S.C., left, and Randy Hultgren, R-Ill., attend a House Financial Services Committee hearing in Rayburn Building titled Semi-Annual Testimony on the Federal Reserves Supervision and Regulation of the Financial System,' November 4, 2015. Federal Reserve Chairwoman Janet Yellen testified. (Photo By Tom Williams/CQ Roll Call)