FBI Director Chris Wray said Tuesday that he would not describe the federal government's surveillance, such as that conducted on President Donald Trump's 2016 campaign, as "spying," as Attorney General William Barr has.

During a Senate Appropriations subcommittee hearing, Wray was asked by Sen. Jeanne Shaheen, D-N.H., about Barr's statement last month that "spying did occur" on the Trump campaign.

"I was very concerned by his use of the word spying, which I think is a loaded word," Shaheen said. "When FBI agents conduct investigations against alleged mobsters, suspected terrorists, other criminals, do you believe they're engaging in spying when they're following FBI investigative policies and procedures?"

"That's not the term I would use," Wray said of "spying." "So, I would say that's a no to that question."

Asked if he had "any evidence that any illegal surveillance" into the Trump 2016 campaign occurred, Wray said he did not.

"I don't think I personally have any evidence of that sort," Wray said.

At another point, Wray was asked if he felt the federal government "spied into the 2016 presidential election," and replied that he didn’t "think it would be right or appropriate" to share his thoughts and that he wanted to respect an ongoing investigation by the Department of Justice inspector general into aspects of the Russia inquiry.

Wray's answers on Tuesday would appear to contradict Barr's testimony from last month, when he told Shaheen during a committee hearing that he felt "spying did occur" by the U.S. government on Trump's 2016 campaign.

Barr had also said he was "reviewing the conduct" of the FBI's Russia probe during the summer of 2016, and that the Department of Justice inspector general would release a report on the agency's use of the Foreign Intelligence Surveillance Act process and other matters in the Russia case in May or June.

During Tuesday's hearing, Wray was also asked whether domestic terrorism is on the rise.

Wray said the FBI assesses that the threat, including from white supremacists, is serious and persistent.

However, he said, "I don't know that we've seen an increase."

He said the FBI has about 1,000 open domestic terrorism cases, which is about the same number he said the bureau had around the time he became director in 2017.