Rahm Emanuel Resigns As White House Chief Of Staff To Run For Mayor of Chicago

Although no final decision has been made because of family considerations, ABC News has learned that White House officials are preparing for Chief of Staff Rahm Emanuel to announce on Friday -- as Congress adjourns for recess -- that he is leaving his post to explore a run for mayor of Chicago.

White House officials expect that President Obama will also name an interim chief of staff, perhaps senior adviser Pete Rouse, at the announcement.

White House chief of staff Rahm Emanuel, one of President Barack Obama's most powerful aides, plans to step down on Friday to pursue a run for Chicago mayor, sources familiar with the matter said on Thursday.

Obama was to make an announcement at a White House East Room event on Friday. White House spokesman Robert Gibbs would not confirm Emanuel was the subject of the announcement but the sources said Emanuel's announcement would come on Friday.

Former White House chief of staff Rahm Emanuel finally acknowledged Sunday he is preparing to run for mayor of Chicago, releasing a video statement on his new Web site that touches on some of the city's hot-button issues.

In his first substantive comments since Mayor Richard Daley announced he wasn't seeking a record seventh term, Emanuel said he wants to hear from residents on issues from crime to the city budget deficit "as I prepare to run for mayor."

Emanuel, a former Chicago congressman, has long wanted to run for the post if Daley didn't, but first had to arrange his exit as President Barack Obama's chief of staff.