The director of the National Security Agency is expected to depart in April, giving President Obama a chance to retool the intelligence agency after revelations it engaged in widespread surveillance of U.S. citizens, key senators confirmed Wednesday.

Army General Keith Alexander has spent eight years leading the agency but is expected to retire in the coming months after a turbulent year when the NSA's monitoring of phone and Internet traffic was exposed by former contractor Edward Snowden.

Snowden's revelations that the agency is engaged in the collection of private citizens' telephone, email and social-media data sparked outrage on Capitol Hill and among world leaders.

Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., said Alexander told her he was planning to retire in April.

“My understanding is it's April – that's what I was told by him,” she told the Washington Examiner.

But Feinstein disputed whether the Obama administration would use his departure as a chance to reshape the agency and re-balance its mandate to protect national security with new privacy protections.

“I don't know what the word ‘retool’ means...I wouldn't use that expression at all,” she said, noting that her committee is working on a bill that would change the agency's surveillance activity in the wake of Snowden's revelations.

Reuters first reported Alexander's plans to leave, along with his civilian deputy, John “Chris” Inglis, who is expected to depart by the end of the year. NSA spokeswoman Vanee Vines said Alexander plans to leave office in the spring after three extensions to his tenure, according to the report.

“This has nothing to do with media leaks, the decision for his retirement was made prior; an agreement was made with the [Secretary of Defense] and the chairman for one more year – to March 2014,” she said.

Intelligence Committee ranking member Sen. Saxby Chambliss, R-Ga., said Alexander was scheduled to retire but that he encouraged him to remain in his post. He declined to respond to any other questions about the NSA chief.

A leading congressional critic of the Obama administration's domestic surveillance, Sen. Ron Wyden, D-Ore., said he was deeply displeased with Alexander’s public claim in early June that the agency doesn't “hold data” on American citizens.

“I was extremely troubled when the head of the NSA said, ‘We don't hold data on U.S. citizens.’ I've made that clear,” he said.

Documents leaked from Snowden later revealed that the NSA had broken privacy rules or overstepped its legal authority thousands of times each year since 2008.

“I think it's very clear that the challenge now is to strike a better balance between ensuring to the American people that there can be policies that can protect both security and civil liberties – and that would be the next challenge for the person who takes over at NSA,” Wyden said.

Wyden and Sen. Mark Udall, D-Colo., have been warning for more than two years that the NSA has been conducting a massive dragnet on phone and Internet records. They wrote a bill that would limit the federal government's ability to collect data on Americans without a demonstrated link to terrorism or espionage and reform the way the Foreign Intelligence Surveillance Court operates.

Those who defend the NSA surveillance activity as necessary to national security worry that Alexander is being scapegoated.

Sen. Lindsey Graham, R-S.C., said the NSA chief has done an outstanding job and he's sorry to see him go.

“At the end of the day, I just worry that we're going to go back to a pre-9/11 mentality,” Graham said. “It would be sad if we lost him as a sacrificial lamb.”