CUSTER, SD -- South Dakota Sen. John Thune said he's open to serving as Mitt Romney's running mate, telling reporters in his home state on Wednesday that it would be tough to ever rule out that option.

"I don’t think you ever rule out or say no to opportunities to public service if you are really interested in making a difference for your country, you want to put your gifts and abilities to the highest and best use,” Thune told reporters following a town hall in the local firehouse here. But, he added, "I don’t expect that to happen but I don’t think you never say never when it comes to serving your country."

Thune seems to have shifted in the way he's spoken about about his contact with the Romney campaign. Just two weeks ago, the senator told The Hill, he had yet to be contacted by the Romney campaign. But today, Thune said, “We talk to him all the time.”

Other than knowing who is leading the search, Romney’s vice presidential selection process has been rather secretive. Thune’s comments come on the same day one of Romney’s top advisers, John Sununu, gave National Reviewone of the first glimpses into the grueling process. Sununu said Thune is “on the list for consideration” for VP.

The small town senator, who even flirted with running for president himself this cycle, seems happy with his current position as the third-ranking Republican in the U.S. Senate.

Being vice president for Thune, he says, is “not a job I aspire to.”

"I like the job I have. I look forward to working with a president, as a member of the United States Senate, that is interested in solving problems," he said. "I think that Gov. Romney and his team will make a very good choice. I think, some of the names I am hearing banging about out there are really good people."

Sources say the senator may soon hit the campaign trail for Romney, perhaps in neighboring Iowa. Thune endorsed Romney in Des Moines, Iowa just before Thanksgiving -– weeks before many other prominent Republicans picked a candidate.

“I came out and supported him [Romney] early because I thought he…represented our best opportunity to win in November and also the guy who was best experienced and had the best skills to govern our country for the next few years, which is not going to be easy,” Thune said, standing in front of a Custer fire truck the day after Romney secured the required 1,144 delegates for the party’s nomination. “I am delighted he has crossed that line and is going to be our nominee because I think it is going to be a great race this fall.”