San Diego City Council President Todd Gloria, a Democrat, stepped in to take over the mayor's job after Bob Filner resigned following multiple allegations of harassment.
Gloria said in a stamen Tuesday that he wishes to focus on being interim mayor and city councilman.
There was speculation that Republican Carl DeMaio, a former city councilman, would run for mayor. DeMaio said Tuesday he will stay in a race for Congress.
DeMaio said he would renew his attention on previously announced plans to challenge Rep. Scott Peters, D-San Diego, in a congressional race next year, while Supervisor Ron Roberts said he preferred to finish his term with the county.
Councilman Kevin Faulconer is set to announce whether he'll run at a Wednesday news conference on Harbor Island.
If no one wins a majority in the Nov. 19 election to replace him, the top two contenders advance to a runoff.
The Associated Press and City News Service contributed to this report.