Phoenix Mayor Greg Stanton's resignation becomes official

Phoenix Mayor Greg Stanton's resignation became official at noon on Tuesday.

According to a letter to City Clerk Cris Meyer on May 21, Stanton cited Arizona's "Resign to Run" law as the reason behind his resignation.

"I look forward to new opportunities to serve the people of Phoenix and our entire community," read a portion of the resignation letter.

In October 2017, Stanton announced he will run for the Democratic nomination for Arizona's 9th Congressional District. The seat is currently held by Rep. Kyrsten Sinema, who is running for the U.S. Senate seat held by GOP Sen. Jeff Flake.

According to his profile on the City of Phoenix's website, Stanton was first elected mayor in 2011, and was re-elected in 2015.

Sen. Flake announced in October 2017 he would not run for re-election in 2018.