LAS VEGAS - With a brilliant full moon rising over the horizon, President Obama tonight told thousands of supporters gathered here for an outdoor rally that he's "looking forward" to facing off with Republican rival Mitt Romney on a debate stage Wednesday night in Denver.

"You may have heard that in a few days my opponent in this election and I are going to have a debate. I'm looking forward to it," Obama said, making his first public comments on the highly anticipated showdown.

"I know folks in the media are speculation already on who's going to have the best zingers … about who's going to put the most points on the board," he said, moving to qualify expectations.

The enthusiastic crowd interrupted him with shouts of "You are!"

"Oh no, Gov. Romney, he's a good debater," Obama responded with a chuckle and grin.

The president suggested he planned to use the televised forum as an opportunity to engage his challenger on issues of substance.

"What I'm most concerned about is having a serious discussion about what we need to do to keep the country growing and restore security for hard working Americans," he said. "That's what people are going to be listening for, that's the debate that you deserve."

Obama will spend the next three days holed up with his team of advisers at the Westin Lake Las Vegas Resort in Henderson preparing for the first debate.