U.S. personnel chief Katherine Archuleta resigned Friday in the wake of massive data breach that allowed hackers to steal the records of more than 21 million people under her watch, Fox News confirmed.

Archuleta submitted her resignation to President Obama Friday morning. Her resignation is effective at the close of business today.

She will be replaced by Beth Cobert, who currently works in the White House budget office, White House sources told Fox News. 

"This is the absolute right call,” House Oversight and Government Reform Chairman Jason Chaffetz said in a written statement following the announcement. “OPM needs a competent, technically savvy leader to manage the biggest cybersecurity crisis in this nation's history. The IG has been warning about security lapses at OPM for almost a decade. This should have been addressed much, much sooner but I appreciate the President doing what's best now.”

Calls for Archuleta to go grew in recent weeks following a massive government data breach on her watch.

More On This...

Less than 24 hours earlier, Archuleta had rebuffed demands that she resign, telling reporters she had no intention of leaving and that her agency was doing everything it could to address concerns about the safety of data in its hands.

But on Friday morning, Archuleta told Obama it was best for her to step aside to let new leadership respond to the recent breaches and to improve systems to lessen risks in the future. 

White House spokesman Josh Earnest insisted Friday that Archuleta submitted her resignation at her own volition, and added it is "quite clear" to the president that new leadership at OPM is desperately needed. 

In a statement, Archuleta made no direct reference to the data breach, saying only that she believed it was best to allow the agency to "move beyond the current challenges." She praised the agency's employees as "some of the most dedicated, capable and hardworking individuals in the federal government."

"I have complete confidence in their ability to continue fulfill OPM's important mission of recruiting, retaining and honoring a world-class workforce to serve the American people," Archuleta said.

Archuleta's position appeared to become unsustainable given the scope of the data breach and the mounting calls from lawmakers in both parties for her to resign. On Thursday, within hours of the Obama administration releasing new details about the scope of the breach, House Republican leaders demanded new leadership in the agency, and a number of Democrats followed.

California Rep. Adam Schiff, the senior Democrat on the House Intelligence Committee, said Archuleta's resignation "will help to restore confidence in an agency that not only poorly defended sensitive data of millions of Americans but struggled to respond to repeated intrusions."

"This change in leadership is also an acknowledgement that we cannot simply place blame on the hackers, but need to take responsibility for the protection of personal information that is so obvious a target," Schiff said.

Fox News' Joy Lin and The Associated Press contributed to this report.