Attorney General Bill Barr, in an exclusive interview with Fox News, said the country must know “exactly what happened” with counterintelligence activities conducted during the 2016 election -- and he is determined to get to the bottom of the case.

In his first interview since becoming attorney general, Barr spoke to “America’s Newsroom” host Bill Hemmer during a visit to El Salvador for meetings with law enforcement officials. In pointed terms, he fired back at Democrats who have castigated him over his handling of Special Counsel Robert Mueller's report -- calling Speaker Nancy Pelosi's charge that he lied to Congress "laughable" and dismissing an attempt to hold him in contempt of Congress.

"That's part of the usual ... political circus that's being played out. It doesn't surprise me," he said.

And the nation's top law enforcement official provided new details about the recently announced probe into the origins of the Russia investigation, defending his decision to pursue it and stressing that many of the answers he's gotten so far have been "inadequate."

US ATTORNEY JOHN DURHAM HAS BEEN REVIEWING ORIGINS OF RUSSIA PROBE 'FOR WEEKS:' SOURCE

“The first step is to find out exactly what happened, and we're trying to get our arms around that, getting all the relevant information from the various agencies and starting to talk to some of the people that have information,” Barr told Hemmer.

While the decision to look back at the origins of the investigation has prompted harsh criticism from Democrats who previously have accused him of acting as the president's lawyer, Barr argued there's much yet to learn.

“I think there's a misconception out there that we know a lot about what happened,” he said.

“The fact of the matter is Bob Mueller did not look at the government's activities. He was looking at whether or not the Trump campaign had conspired with the Russians. But he was not going back and looking at the counterintelligence program. And we have a number of investigations underway that touch upon it -- the main one being the office of inspector general that's looking at the FISA warrants.”



LISTEN TO THE FULL INTERVIEW ON THE LATEST "HEMMER TIME" PODCAST

Barr specifically acknowledged that the period between Election Day and Inauguration Day will be key, saying “some very strange developments” took place in that time – including the early January 2017 briefing intelligence officials gave to the president at Trump Tower and “the leaking of information subsequent to that meeting.”

At that meeting, Trump was briefed on Russian meddling and was informed by then-FBI boss James Comey about the allegations against him in a salacious and unverified dossier. Details later leaked to the press.

“That's one of the things ... we need to look at,” Barr said of the briefing.

Barr's review could prove as politically explosive as the Russia probe itself. President Trump is watching closely, and tweeted Friday morning that those who spied on his campaign committed "treason" and could face "long jail sentences." It comes as congressional Democrats ramp up their own investigations into the Trump administration, including looking at obstruction allegations in connection with the Russia case.

It emerged earlier this week that hard-charging U.S. Attorney John Durham was tapped to examine the origins of the Russia investigation, and has been working on his review “for weeks.” Bill Barr assigned Durham to conduct the inquiry into alleged misconduct and alleged improper government surveillance on the Trump campaign in 2016 as well as whether Democrats improperly colluded with foreign actors.

Durham will focus on the period before Nov. 7, 2016—including the use of FBI informants, as well as alleged improper issuance of Foreign Intelligence Surveillance Act (FISA) warrants. Durham was asked to help Barr to "ensure that intelligence collection activities by the U.S. Government related to the Trump 2016 Presidential Campaign were lawful and appropriate."

A source also told Fox News that Barr is working "collaboratively" on the investigation with FBI Director Chris Wray, CIA Director Gina Haspel, and Director of National Intelligence Dan Coats, and that Durham is also working directly with Justice Department Inspector General Michael Horowitz, who is currently reviewing allegations of misconduct in issuance of FISA warrants, and the role of FBI informants during the early stages of the investigation.

In his interview Friday, Barr said he stressed it is of the utmost importance “to find out what the government was doing during that period.”

“I've been trying to get answers to questions and I found that a lot of the answers have been inadequate. And I've also found that some of the explanations I've gotten don't hang together,” Barr told Hemmer.

“So in a sense, I have more questions today than I did when I first started. Some of what things don't hang together, some of the explanations of what occurred. People have to find out what the government was doing during that period. If we're worried about foreign influence, for the very same reason shouldn’t we be worried about whether government officials abused their power and put their thumb on the scale?”

He added: “I'm not saying that happened, but I'm saying that we have to look at that.”

Barr then turned his attention to Pelosi, D-Calif., and her recent claims that he lied under oath.

BARR TEASES PELOSI, ASKS IF SHE BROUGHT HER HANDCUFFS ON SIDELINES OF DC EVENT

“It's a laughable charge and I think it's largely being made to try to discredit me partly because they may be concerned about the outcome of a review of what happened during the election,” Barr countered.

“They may be trying to undermine my credibility, but obviously you can look at the face of my testimony and see on its face that there was nothing inaccurate about it.”

Earlier this month, Pelosi alleged that the attorney general “lied to Congress.” She was apparently referring to an April 9 hearing, where Rep. Charlie Crist had asked whether Barr knew what prompted reports that prosecutors on the special counsel team were frustrated with his initial summary of their findings. Barr said he did not. But The Washington Post reported that Mueller had contacted Barr to express concerns about that summary, though he reportedly was concerned largely about the media coverage of it.

As Barr also battles congressional Democrats over their push for access to the full Mueller report and underlying documents -- a fight that saw a key committee call for holding him in contempt -- the attorney general seemingly teased Pelosi on the sidelines of a Capitol Hill event this week.

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According to a source close to the attorney general, Barr approached her in a holding tent after the Wednesday event and asked whether she had brought her handcuffs.

The quip was a reference to calls from some rank-and-file Democrats for Barr himself to be arrested, amid the fight over access to Russia probe documents.

Fox News' Brooke Singman and Jake Gibson contributed to this report.