Secretary of Defense Chuck Hagel is stepping down after having conducted a series of meetings with President Barack Obama over the past several weeks, multiple sources confirmed Monday morning.

Although Hagel will stay on the job until his replacement is confirmed, an official stated that a successor will be named "in short order," according to The New York Times.

The stunning move comes amid criticism of the president's national security team on a range of global issues, including the threat posed by the militant group known as the Islamic State, or ISIS, senior defense officials confirmed to NBC News, adding that the 68-year-old was forced to resign following pressure from Obama.

Hagel, who was the first enlisted combat veteran to lead the Department of Defense, took the position in February 2013 after the departure of longtime Democratic Party insider Leon Panetta.

The announcement about Hagel's resignation is expected to be made by Obama at the White House at 11:10AM ET Monday, Fox News reported.

Reportedly, Obama asked the sole Republican on his national security to step down and resign on Friday after the White House is believed to have lost confidence in his ability to live up to his role at the Pentagon, with one senior official saying, "He wasn't up to the job."

However, another senior administration official confirmed that Hagel, a former U.S. senator who was confirmed last year after a bruising confirmation process, has been discussing a departure from the White House "for several weeks" and had initiated talks about his resignation himself, with Obama mutually agreeing to his decision to leave.

"Over the past two years, Secretary Hagel helped manage an intense period of transition for the United States Armed Forces, including the drawdown in Afghanistan, the need to prepare our forces for future missions, and tough fiscal choices to keep our military strong and ready," the official said, NBC News reported.

"Over nearly two years, Secretary Hagel has been a steady hand, guiding our military through this transition, and helping us respond to challenges from ISIL to Ebola. In October, Secretary Hagel began speaking with the President about departing the Administration given the natural post-midterms transition time."

Meanwhile, Hagel's replacement for Defense Secretary position will have to confront a host of issues, most notably the Obama administration's military campaign against ISIS. The Times named three people reportedly on a short list to replace him, including a woman.