President Donald Trump told Ukraine's president at least five times that he would task Attorney General William Barr with assisting him in investigating former Vice President Joe Biden, according to the call summary released by the White House Wednesday.

"There’s a lot of talk about Biden’s son, that Biden stopped the prosecution and a lot of people want to find out about that so whatever you can do with the Attorney General would be great," Trump said, according to a memorandum of the conversation with Ukrainian President Volodymyr Zelenskiy

The Justice Department has denied that Barr and Trump ever went on to have any conversation on the matter, but Democrats expressed fury Wednesday over the comments, which suggest the president was prepared to try and task the country's lead law enforcement official with pushing forward an investigation into his political opponent.

"What adds another layer of depravity to this conversation is that the President of the United States then invokes the Attorney General of the United States as well as his personal lawyer as emissaries," House Intelligence Chairman Adam Schiff, D-Calif., said Wednesday. "In the case of the attorney general, as the official head of the U.S. Department -- the Department of Justice, that will be part and parcel in this."

The episode is likely to heighten scrutiny of Barr, after the Justice Department revealed Wednesday that it had declined to open a criminal probe into President Trump over the call following a referral from the Director of National Intelligence Inspector General Michael Atkinson.

According to an opinion from the DOJ's Office of Legal Counsel, Atkinson determined "the President's actions could involve a "serious or flagrant problem, "abuse," or violation of law, and [Atkinson] observed that federal law prohibits any person from soliciting or accepting a campaign contribution from a foreign national."

The Justice Department's criminal division after reviewing the matter, however, determined that no campaign finance violations occurred, according to a DOJ official who briefed reporters Wednesday, and indicated there are no plans to review the president's actions further.

Driving the decision not to prosecute the case, the official said, was that prosecutors in their legal interpretation concluded that nothing "of value" was clearly promised or exchanged between Trump and Zelenskiy as a result of the call. Though the official also acknowledged that the administration's hold-up of military aid to Ukraine was never examined as a part of their inquiry, explaining that prosecutors saw it as more of a foreign policy matter.

The official said that Barr was not involved at all in the analysis inside the criminal division as to whether Trump's conduct was criminal, noting he was on vacation during most of the review, but said that he was kept aware of developments in the case and the Criminal Division's eventual decision.

DOJ officials told ABC News Wednesday that there was never consideration for Barr to recuse himself from the Criminal Division's review to avoid an appearance of impropriety, and that there was separately no consideration of appointing a special counsel to investigate the complaint.

But that explanation is unlikely to satisfy Democrats in the midst of their impeachment inquiry. House Judiciary Chairman Jerry Nadler said Wednesday that Barr "at a minimum" should recuse himself from any further involvement DOJ may have in the Ukraine investigation, but a DOJ spokeswoman said earlier in the day that following the review the department had "concluded the matter."

Barr has in the past dismissed criticism from Democrats who have cast him as a "protector" of President Trump, based in part on his role in recommending Trump not face criminal charges over the instances of potential obstruction of justice outlined in special counsel Robert Mueller's report on Russian interference in the 2016 election.

In turn, Barr's opening of an inquiry into the origins of the Russia investigation has provided further fuel for President Trump in his attacks against former intelligence officials who launched the investigation.

"The crime was committed on the other side and we will find out about that," Trump said in a July interview with Fox News. "We have a great attorney general who is looking at it. I'm not involved in that."

But his call with Zelenskiy suggests Trump did in fact seek to directly involve himself in Barr's investigation.

Trump alluded to Barr's review by pressing the Ukrainian leader to investigate 'Crowdstrike,' a cybersecurity firm that first disclosed Russia's attempted to infiltrate the Democratic National Committee's servers ahead of the 2016 election, and questioned whether Ukraine currently possesses the DNC server.

"I would like to have the Attorney General call you or your people and I would like you to get to the bottom of it," Trump said, according to the call summary.

A statement released by Justice Department spokesperson Kerri Kupec Wednesday said that Barr's investigation into the origins of the Russia probe, led by U.S. Attorney John Durham, has indeed intersected with Ukraine.

Kupec said while Barr has not been in direct contact with Ukrainian officials on the issue, Durham "is separately exploring the extent to which a number of countries, including Ukraine, played a role in the counterintelligence investigation directed at the Trump campaign during the 2016 election."

"Certain Ukrainians who are not members of the government have volunteered information to Mr. Durham, which he is evaluating," Kupec said.

ABC's Ben Siegel contributed to this report.