ANNAPOLIS, Md. (AP) — Sen. John McCain said Wednesday he has begun “getting together a list of names” to choose a vice presidential running mate, and hopes to make an announcement before the Republican convention in early September.

McCain has given no hint of his thinking on a running mate, although he frequently speaks warmly of his former rivals for the nomination, particularly former Arkansas Gov. Mike Huckabee. Among the other possible choices are several governors: Mississippi’s Haley Barbour, Minnesota’s Tim Pawlenty, Florida’s Charlie Crist,South Carolina’s Mark Sanford and Utah’s Jon Huntsman Jr.

“I’d like to get it done as early as possible. I’m aware of enhanced importance of this issue given my age,” said the Arizona senator, 71.

McCain wrapped up the Republican presidential nomination a month ago.

Interviewed by radio talk show host Don Imus, McCain did not offer any details of his search for a running mate.

“We just started this process of getting together a list of names and having them looked at,” he said.

“If I had a personal preference I’d like to do it before the convention to avoid some of the mistakes that I’ve seen made in the past as you get into a time crunch and maybe sometimes don’t make the announcement right or maybe they have not examined every single candidate.”

McCain made his comments on his way to the U.S. Naval Academy, where he graduated, to deliver the third in a string of speeches in a weeklong tour designed to introduce him to a wider, general election audience.

First he stopped in at Chick & Ruth’s Delly, an eatery down the street from the Maryland Statehouse where crab omelets are on the menu and local and state politicians have gathered for decades for breakfast and shop talk. An American flag hangs over the counter with its five stools, and for nearly two decades, all business has come to a halt for a few seconds as the Pledge of Allegiance is recited.

In his speech on a wind-swept outdoor pavilion overlooking the naval academy football stadium, the Vietnam prisoner of war issued a challenge.

“If you find faults with our country, make it a better one. If you are disappointed with the mistakes of government, join its ranks and work to correct them,” he said.

He said he hopes more Americans will enlist in the military or run for office.

“But there are many public causes where your service can make our country a stronger, better one than we inherited. Wherever there is a hungry child, a great cause exists. … Wherever there is suffering, a great cause exists.”