Attorney General William Barr’s review of the origins of the Russia investigation is focused on U.S. intelligence gathering before the Federal Bureau of Investigation opened its formal inquiry in July 2016, according to an interview he gave to the Wall Street Journal.

“Government power was used to spy on American citizens,” Barr said in the interview published on Friday. “I can’t imagine any world where we wouldn’t take a look and make sure that was done properly.”

“Just like we need to ensure that foreign actors don’t influence the outcome of our elections, we need to ensure that the government doesn’t use its powers to put a thumb on the scale,” he added.

Barr is working closely with CIA Director Gina Haspel, Director of National Intelligence Dan Coats, and FBI Director Christopher Wray, according to the WSJ. His review is not a criminal investigation “at this point,” the newspaper reported. There is no timetable for its completion.

The attorney general discussed why he chose John Durham, Connecticut’s U.S. attorney, to lead the review.

“I was looking for someone who is tenacious, who is used to looking at sensitive material involving government activities, who has a reputation for being fair and evenhanded,” he said.

Barr did not discuss what he has discovered so far, but he told the paper that he was surprised that officials have not been able to answer many of his questions.

“I have more questions now than when I came in,” he said.

Former FBI officials have testified that they opened the counterintelligence investigation on July 31, 2016, after they received information from the Australian government that a foreign policy campaign adviser, George Papadopoulos, told an Australian diplomat that he was told the Russians had “dirt” on Hillary Clinton.

As Papadopoulos has detailed to Breitbart News and other outlets, the person who told him the Russians had dirt was a Maltese academic named Joseph Mifsud.

Papadopoulos has discussed in interviews the odd circumstances around the introduction. He said he met Mifsud through a woman in London who used to work for the FBI, who told him that Mifsud would introduce him to a lot of important people who would help him on the campaign.

It has later emerged that an FBI informant named Stefan Halper separately met Carter Page at a conference in London in mid-July. Halper would later reach out to Papadopoulos, bringing along a young woman who introduced herself as a research assistant named “Azra Turk.”

The New York Times recently reported that the woman was a “government investigator” who oversaw the operation with Halper to gain more information from Papadopoulos.

The FBI in October 2016 obtained a warrant to surveil Page, using opposition research gathered by ex-British spy Christopher Steele for the firm Fusion GPS, which was commissioned by the Clinton campaign and the Democratic National Committee.