(Pat Sullivan/AP, File) (Pat Sullivan/AP, File)

San Antonio Mayor Julian Castro, the keynote speaker at the 2008 Democratic National Convention, will attend next month's Steak Fry hosted by Sen. Tom Harkin (D-Iowa), according to a person with knowledge of the event.

The Steak Fry, now in its 36th year, is a regular stopover for potential presidential candidates trying to make inroads in the Hawkeye State. A relatively new senator named Barack Obama attended the Steak Fry in 2006, shortly before launching his 2008 presidential campaign.

The event takes place this year on Sept. 15 in Indianola, Iowa. The news was first reported by the Des Moines Register.

But Castro said in an interview earlier this year that he won't run for president in 2016.

Asked about a potential 2016 run (which few expect from the mayor) by PolicyMic, Castro responded: "Who? I? Me? No, I'm not going to. But it'll be great to see all of that as it bubbles on."

Castro is just 38 years old, meaning he's got plenty of political years in front of him. He won reelection to his current job this year and has said he won't run for governor in 2014 either.

Several politicians who are getting more 2016 buzz than Castro are in Iowa this weekend.

Updated at 3:00 p.m.