Republican presidential hopeful Herman Cain said Sunday that an Internet ad featuring his campaign manager smoking conveyed a message about letting "people be people" and was not intended to suggest that smoking is cool.

The video went viral this month with some 1 million clicks on Cain's campaign website. The ad shows Cain's top adviser, Mark Block, taking a deep drag from a cigarette and slowly exhaling into the camera.

"I'm not a smoker. But I don't have a problem if that's his choice," Cain said on CBS' "Face the Nation."

"So let Herman be Herman. Let Mark be Mark. Let people be people. This wasn't intended to send any subliminal signal whatsoever," the candidate said.

Cain, who was diagnosed with liver and colon cancer in 2006 and has said he's been cancer-free since 2007, was chided about the ad by his interviewer, Bob Schieffer, a bladder cancer survivor.

"Mark Block smokes. That's all that ad says," Cain said. "We weren't trying to say it's cool to smoke. You have a lot of people in this country that smoke. But what I respect about Mark as a smoker ... he never smokes around me or smokes around anyone else. He goes outside."

Cain said the video was meant "to be informative. If they listen to the message where he said America has never seen a candidate like Herman Cain, that was the main point of it. And the bit on the end, we didn't know whether it was going to be funny to some people or whether they were going to ignore it or whatever the case may be."

Cain said he understood the objection and that about 30 percent of the feedback the campaign had received to the video was similar to Schieffer's.

Schieffer pressed Cain to send an anti-smoking message on the show. Cain complied.

"Young people of America, all people, do not smoke. It is hazardous and it's dangerous to your health. Don't smoke. I've never smoked and I have encouraged people not to smoke," he said.