Phoenix Mayor Greg Stanton has announced he will resign from office on May 29 as he prepares for a Congressional run.
In a letter sent to the city clerk on Monday, Stanton said, "Our city is in strong shape and I am proud that we have put Phoenix on the most positive trajectory of any large city in America."
Stanton announced in October that he would be running to fill the seat held by Rep. Kyrsten Sinema, who herself is now running to fill Jeff Flake's Senate seat.
Mayor Stanton took office in 2012, and prior to that, he spent nine years on the City Council and as Arizona's Deputy Attorney General.
In a video linked from his campaign site, Stanton said, "I'm running for Congress because we deserve better than we're getting."
Vice Mayor Thelda Williams will serve as mayor until the council votes on an interim mayor, spokeswoman Raquel Estupinan told KGUN's sister station KNXV.