WASHINGTON--White House chief of staff Rahm Emanuel is poised to quit the White House as early as Friday to launch his bid to run for mayor of Chicago, the Chicago Sun-Times has learned.

A source close to Emanuel said "Rahm is nearing a decision on whether to leave the White House and explore a run for Mayor of Chicago; an announcement could come as early as Friday. Because of family considerations, no final decision has been made."

President Obama said Monday that White House chief Rahm Emanuel needs to make "a decision quickly" about running for mayor of Chicago. The word from the Emanuel source confirms what I reported last week that all signs point to Emanuel leaving the White House to move back to Chicago and run for mayor in the Feb. 22 primary.

In an interview with NBC's Matt Lauer on "The Today Show," Obama said, "Well, I think that Rahm will have to make a decision quickly, because running for mayor of Chicago is a serious enterprise. And I know this is something he's thinking about."

Asked if he would endorse Emanuel for mayor, Obama reminded Lauer that he already said Emanuel would make "an excellent mayor. But until he makes a decision, I'm not going to be making decisions about how I'm going to approach it."

Emanuel is the only Chicago mayoral contender who has been mute--totally--not a word on the record--about his thoughts on running for mayor. What we know--on the record--has been channeled through third parties who have talked to Emanuel such as White House senior advisor David Axelrod, Rep. Danny Davis, Rep. Mike Quigley and others.

Obama is likely to tap advisor Pete Rouse--who served as Obama's chief of staff when he was an Illinois senator--as interim chief of staff upon Emanuel's departure, but no final decision has been made.