Obama spokesman Robert Gibbs would not confirm that the announcement is about Emanuel, but two people close to Emanuel say he will resign on Friday to begin his campaign for Chicago mayor.
The president is also expected to name an interim chief of staff, likely to be senior adviser Pete Rouse. Gibbs said the president has "complete loyalty and trust" in Rouse, though he wouldn't confirm that Rouse had been tapped for the interim post.
The president is likely to choose a permanent chief of staff after the Nov. 2 midterm elections.
