WASHINGTON — Attorney General Jeff Sessions gave a vote of confidence Friday to former FBI director Robert Mueller, the special counsel leading an investigation into potential coordination between Russia and the Trump campaign, but he also said he hoped the probe could “move forward and come to an end sooner rather than later.”

The attorney general’s comments during a “Fox & Friends” interview were his most expansive to date on the Justice Department’s appointment last month of Mueller to run the investigation.

“Mr. Mueller is someone I’ve known for a long time, and I’ve had confidence in him over the years,” said Sessions, an Alabama Republican who served for years on the Senate Judiciary Committee, the congressional panel that oversees the FBI.

“I feel confident in what he’ll do, that’s all I can say to you about that,” Sessions said. “The man has a good reputation. He knows his business.”

Those remarks stand in contrast to a drumbeat of Republican criticism of the special counsel’s investigation, including from President Donald Trump, who on the same show last week contended that Mueller was “very, very good friends” with fired FBI director James Comey and characterized that relationship as “very bothersome.”

Republicans have also raised conflict-of-interest concerns by noting that some lawyers on Mueller’s investigative team have previously contributed to Democratic candidates, though federal law and department policy does not permit the special counsel to take into consideration the political affiliations of a potential hire.

Still, Sessions said he was hopeful the investigation would conclude sooner than later, a point White House staff has repeatedly made, and he did suggest that questions about the composition of Mueller’s staff could be fair game.

“We expect full integrity and good work from every person involved in this investigation,” Sessions said, later adding, “Mr. Mueller is entitled, lawfully, I guess, at this point, to hire who he desires, but I think he should look for people who have strength and credibility by all people.”

Mueller was appointed FBI director by Republican President George W. Bush and held the position for 12 years.