Acting White House chief of staff Mick Mulvaney continued to back away Sunday from his public acknowledgment of a quid pro quo in which the Trump administration leveraged military aid to Ukraine for an investigation that could politically benefit President Trump, while the top U.S. diplomat defended Trump’s private lawyer’s role in Ukrainian affairs as “completely appropriate.”

“I never said there was a quid pro quo, ’cause there isn’t,” Mulvaney said on Fox News on Sunday, insisting that while he “didn’t speak clearly maybe on Thursday,” there couldn’t have been a quid pro quo because “the aid flowed.”

Mulvaney has struggled to explain his abrupt about-face since a Thursday news conference in which he said Trump “absolutely” raised concerns about the Democratic National Committee server that was hacked in 2016, which according to a debunked conspiracy theory could be in Ukraine and could prove Russia didn’t interfere in the 2016 election.

During that appearance, Mulvaney also told a reporter who pointed out that he had articulated a quid pro quo that “we do that all the time with foreign policy,” listing “three issues” that were involved in the Ukraine decision: corruption, the support other countries were offering and an ongoing Justice Department investigation into the origins of the Russia investigation.

But in a subsequent written statement, and again on Sunday, Mulvaney insisted there were only “two reasons for holding back the aid,” leaving out the Justice Department’s probe, which a department official already disavowed. Mulvaney added that once the administration was able to satisfy concerns that Ukraine was “doing better with” corruption and establish that European nations were giving “a considerable sum of money in nonlethal aid, once those two things cleared, the money flowed.”

Current and former officials who have been providing testimony to the House’s impeachment probe paint a different picture. According to their statements as described by people familiar with their closed-door testimony, the administration was pushing for Ukrainian leaders to conduct investigations into the server and the role of former vice president Joe Biden’s son Hunter on the board of Ukrainian energy giant Burisma probes Trump himself referenced in a July 25 phone call with Ukrainian President Volodymyr Zelensky. The push was largely being driven by the president’s personal lawyer Rudolph W. Giuliani, they said, whom diplomats were told to work with on Ukraine policy, according to Gordon Sondland, the U.S. ambassador to the European Union who said he was disappointed by the directive.

Hunter Biden served for nearly five years on the board of Burisma, Ukraine’s largest private gas company, whose owner came under scrutiny by Ukrainian prosecutors for possible abuse of power and unlawful enrichment. Hunter Biden was not accused of any wrongdoing in the investigation. As vice president, Joe Biden pressured Ukraine to fire the top prosecutor, Viktor Shokin, who Biden and other Western officials said was not sufficiently pursuing corruption cases. At the time, the investigation into Burisma was dormant, according to former Ukrainian and U.S. officials.

Speaking on ABC’s “This Week,” Secretary of State Mike Pompeo refused to say whether Giuliani had been acting in Ukraine with his blessing, arguing that it was his “consistent policy . . . not to talk about the internal deliberations” of the administration. He defended the decision to bring in an outside figure like Giuliani, however, arguing that “it happens all the time.”

“This is completely appropriate,” Pompeo said, pointing out how former Secretary of State Hillary Clinton took advice from Sidney Blumenthal and former ambassador Bill Richardson had been deputized to help on North Korea policy.

Others vehemently disagree.

“Rudolph W. Giuliani running around meeting with heads of state on behalf of the president’s political interests is a profoundly shocking and important thing for us to understand,” Rep. Jim Himes (D-Conn.) said Sunday on CBS’s “Face the Nation.” Himes sits on the Intelligence Committee, one of three House panels conducting the impeachment inquiry.

Not just Democrats are upset. According to the testimony of Fiona Hill, who was the top White House aide on Russia, former national security adviser John Bolton was livid at Giuliani’s involvement, calling him a “hand grenade.”

Bolton also wanted it known, she testified, that he refused to be a part of what he called a “drug deal” between Sondland and Mulvaney, two of the three officials — along with former special U.S. envoy to Ukraine Kurt Volker — who had been tasked to handle Ukraine policy with Giuliani after the ouster of U.S. Ambassador Marie Yovanovitch.

The committees have not yet struck a deal with Bolton to testify in their impeachment probe, though there is significant interest among the panels conducting the investigation to have him come forward.

There appears to be bipartisan interest as well in hearing from Giuliani. Meanwhile, Pompeo said Sunday that he would “do everything I’m required to do by law” if asked to come forward and testify in the probe.

In the coming week, the House panels will host at least five government officials who were in some way connected to the use and redirection of Ukraine military aid, including Michael Duffey, the official at the Office of Management and Budget who signed off on the apportionment letters that froze the money.

Trump directed Mulvaney to hold back the aid to Ukraine a week before his July 25 phone call with Zelensky, upending the traditional process of sending that money out through the State and Defense departments. In his revised statements, Mulvaney has said that the process was slowed not because of a quid pro quo but because of concerns about corruption in Ukraine and the level of contributions from European nations.

For the past five years, the Trump administration and the Obama administration have sent Ukraine increasing amounts of military aid to fend off Russian-backed separatists in its eastern provinces. Before this year, no officials raised the concerns Mulvaney cited to the point of withholding military aid until the last days of the fiscal cycle, a move by the Trump administration that alarmed diplomats and lawmakers of both parties.

“The fact is that pretty much everybody who was inside the White House, from the whistleblower to all of the other witnesses who have released opening statements, had profound discomfort with what Rudolph W. Giuliani was doing and believed . . . that the military aid was being held up for the president’s partisan gain,” Himes said.

Republican lawmakers have challenged Democrats to prove that, however, arguing that the panels should be holding more proceedings in public and releasing to members the transcripts and full contents of the materials witnesses in the impeachment probe are turning over to investigators.

“It’s all being done in secret. . . . If they wanted to do an impeachment, they should be doing this out in the open,” Rep. Devin Nunes (R-Calif.), a member of the House Intelligence Committee, said on Fox’s “Sunday Morning Futures.” “They are creating this false narrative for television. It’s all for sound bites, and it’s an embarrassment to the United States of America.

Democrats say that the materials will be made public and that the delays are the result of a probe that is moving at breakneck pace and being presented every day with “jaw-dropping new information” — such as Mulvaney’s news conference, which Democrats saw as tantamount to a confession.

“There is not one word of testimony, written or spoken, which contradicts the notion that the president used the assets of the United States military aid, a White House meeting, to advance his political interests of getting Ukraine to meddling in the next, the upcoming presidential election,” Himes said.

Kyle Swenson contributed to this report.