Acting White House chief of staff Mick Mulvaney on Sunday defended his claim that President Donald Trump did not withhold nearly $400 million in military aid to Ukraine in order to get Kyiv to undertake investigations of Democratic rivals and the 2016 election.

Mulvaney told reporters last week there was such a” quid pro quo” by Trump, but hours later walked back the statement and continued to advance his revised version of White House policy discussions in an interview on the “Fox News Sunday” talk show.

“There were two reasons we held up the aid,” Mulvaney said. “The first one was the rampant corruption in Ukraine. It’s so bad in Ukraine that in 2014 Congress passed a law … requiring us to make sure that [the fight against] corruption was moving in the right direction. So corruption’s a big deal. Everybody knows it.”

He added, “The president was also concerned about whether other nations, specifically European nations, were helping with foreign aid to Ukraine.”

FILE – White House chief of staff Mick Mulvaney talks to the press at the White House, Oct. 17, 2019.

Mulvaney also mentioned during his White House news conference last Thursday that Trump wanted to know whether Ukraine had possession of a computer server used at the Democratic National Committee in 2016 as it supported former U.S. Secretary of State Hillary Clinton in her unsuccessful campaign against Trump for the White House. The whereabouts of the computer is part of a debunked theory that Ukraine had meddled in the 2016 election, and not Russia, as the U.S. intelligence community concluded.

But Mulvaney said Sunday his mention of Trump’s concerns about the computer “wasn’t connected to the aid,” although last week had said, “That’s why we held up the money.”

“We do that all the time with foreign policy,” Mulvaney had said at the White House.

On Sunday, he said, “I never said there’s a quid pro quo because there isn’t.”

Trump, while initially blocking the aid to Ukraine, eventually released the money to Kyiv.

“The aid flowed,” Mulvaney said Sunday. “Once we were able to satisfy ourselves that corruption, that they were doing better with it…” and other countries’ aid to Ukraine had increased, “the money flowed.” During the news conference last week, Mulvaney added a third condition, whether Ukraine was assisting a U.S. Justice Department probe of the origins of 2016 election investigations that eventually implicated Russia’s interference to help Trump win.

FILE – Ukraine’s President Volodymyr Zelenskiy and U.S. President Donald Trump face reporters during a bilateral meeting on the sidelines of the 74th session of the United Nations General Assembly in New York, Sept. 25, 2019.

Trump’s interactions with Ukrainian President Volodymyr Zelenskiy are at the center of the impeachment inquiry Democrats in the House of Representatives have opened against Trump.

The inquiry was touched off when an intelligence community whistleblower expressed concern about Trump’s July 25 telephone call with Zelenskiy, with a White House-released transcript of the call showing Trump urging the Ukrainian leader to open a corruption investigation into one of his key 2020 election rivals, former Vice President Joe Biden, as well as a probe of his son Hunter Biden’s lucrative position on the board of a Ukrainian energy company.

Both Bidens have denied any wrongdoing, although the younger Biden, 49, said last week he used “poor judgment” in agreeing to work for the Ukrainian company because of the political fallout for his father.

Trump has alleged that when Joe Biden was U.S. vice president, he threatened to withhold loan guarantees to Ukraine unless an earlier corruption probe into the gas company was stopped.

No evidence of wrongdoing by the Bidens has surfaced. But reaching out to a foreign government to dig up dirt on a rival is considered to be interference in a presidential election.

Trump has described his call with Zelenskiy as “perfect” and accuses the Democratic-led House of a witch hunt.

 A House vote for Trump’s impeachment in the coming weeks is a possibility, although his conviction after a trial in the Republican-majority Senate and removal from office remains unlikely.

U.S. Ambassador to the European Union Gordon Sondland, center, arrives for a joint interview with the House Committees on Capitol Hill, Oct. 17, 2019.

Trump donor Gordon Sondland, the U.S. ambassador to the European Union, told impeachment investigators last week that Trump ordered him and other diplomats to work with the president’s personal lawyer, Rudy Giuliani, to pressure Ukraine into investigations that could help Trump politically.

Those investigations would include the 2016 election and the Ukrainian gas company where Hunter Biden worked.

Sondland told the investigators he was disappointed that Trump directed diplomats to work with Giuliani on Ukraine matters.

“Our view was that the men and women of the State Department, not the president’s personal lawyer, should take responsibility for all aspects of U.S. foreign policy towards Ukraine,” Sondland said.

He said the diplomats who worked with Giuliani did not know “until much later” that Giuliani would push for a probe of Biden “or to involve Ukrainians, directly or indirectly, in the president’s 2020 re-election campaign.”

“Let me state clearly: Inviting a foreign government to undertake investigations for the purpose of influencing an upcoming U.S. election would be wrong,” Sondland said in his statement. “Withholding foreign aid in order to pressure a foreign government to take such steps would be wrong. I did not and would not ever participate in such undertakings.”