Brian Williams pulled himself off the "NBC Nightly News" desk for a brief suspension, but his time away from the program may extend longer than anticipated, perhaps even permanently.

NBC's top execs are determining whether to let Williams go or impose a more substantial suspension that would include another on-air apology, this time more heartfelt and specific to the allegations. NBC Universal CEO and President Steve Burke, NBCUniversal News Group CEO Pat Fili-Krushel and NBC News chief Deborah Turness will likely make their decision by the end of this week, according to The Hollywood Reporter.

The NBC executives excluded Williams from a meeting over the weekend, but the embattled anchor did meet with Burke at his Manhattan apartment on Tuesday morning.

Williams' troubles started when he falsely claimed that a rocket-propelled grenade hitting his helicopter while covering the Iraq war in 2003. Military personnel on the ride with him quickly corrected his story on social media, forcing the newsman to recant his version on the Feb. 3 broadcast of "Nightly News."

"I made a mistake in recalling the events of 12 years ago. It did not take long to hear from some brave men and women in the air crews who were also in that desert," Williams said from the desk. "I want to apologize... This was a bungled attempt by me to thank one special veteran and by extension our brave military men and women."

NBC News has since launched an internal investigation into all of Williams' reporting including his time in Iraq, his coverage of Hurricane Katrina and other stories that have come under fire. Richard Esposito, the head of NBC's investigative unit, is leading the investigation.

Speculation has also begun on who could replace Williams in the case that he is fired. Names reported so far include "Today" anchors Matt Lauer, Savannah Guthrie and Willie Geist as well as Carl Quintanilla from CNBC. Lester Holt, who Williams appointed to fill in for him, could take over the job full time or the man who Williams succeeded - Tom Brokaw.

Former "Today" co-anchor Katie Couric recently denied reports that she would return to the network. She's currently the Global Anchor for Yahoo News.