Chris Christie: "Don't worry," I'll be on top stage in next debate

When the next Republican presidential debate airs in September, New Jersey Gov. Chris Christie promises that he'll appear on the first debate stage, where only the top 10 GOP hopefuls will be able to make their case.

"I'll be on the first stage," Christie told "Face the Nation" moderator John Dickerson in an interview to air Sunday. "So don't worry about it."

September's Republican debates, hosted by CNN, will feature two stages. One-half will comprise only the top 10 candidates "according to public polling." The other half will include any candidate with more than 1 percent in the polls.

With the spotlight trained on the likes of billionaire Donald Trump -- whose immigration proposals have become a focal point of the 2016 policy debate -- and GOP establishment favorite Jeb Bush, Christie has recently found himself lagging in national surveys. In the latest CBS News poll among Republicans, the New Jersey governor placed ninth, with only 3 percent of GOP voters throwing their support behind him.

When Christie sat down for an interview in Iowa, however, he remained convinced that the current numbers reflected little of what voters would think down the line.

"We know that people, especially in the state we're sitting in right now and in New Hampshire, they don't make their minds up till very, very late," the Republican governor said.

Christie is banking on his efforts on the ground to garner votes, saying, "It's just work hard. That's what you have to do. And so we'll just continue to work really hard."

"You lay out your message and your vision for the country," he added. "And then we're going to do just fine."

Watch the full interview with New Jersey Gov. Chris Christie on CBS' "Face the Nation," airing Sunday, August 23, at 10:30 a.m. ET.