Republican presidential candidate Rick Perry isn't backing down from making an issue out of President Barack Obama's birth certificate.

"It's a good issue to keep alive," Perry reportedly told CNBC's John Harwood Monday.

"Look I haven't seen his, I haven't seen his grades," he added. "My grades ended up on the front page of the newspaper, so let's you know, if we're going to show stuff, let's show stuff, but look that's all a distraction, I mean I get it. I'm really not worried about the president's birth certificate. It's fun to poke at him a little bit and say 'Hey, how about let's see your grades and your birth certificate.'"

Obama graduated from Harvard Law School magna cum laude, while Perry earned a D in Principle of Economics from Texas A&M University.

Appearing on CNBC Tuesday morning, Harwood said he couldn't tell if Perry was joking about the issue or not.

"It wasn't clear entirely to what to what degree he was trying to be serious and joking at the same time, maybe play both sides of the fence," Harwood recalled.

CNBC's interview focused on Perry's new flat tax plan, which critics say would be a massive tax cut for the wealthy.

"Those that want to get into the class warfare and talk about, 'Oh my goodness, there going to be some folks here that make more money out of this or have access to more money,' I'll let them do that," he explained.

Perry first raised questions about Obama's birth certificate in an interview published in PARADE magazine over the weekend.

When asked if he believed the birth certificate was real, Perry said he “[didn't] know.”

"I had dinner with Donald Trump the other night,” the presidential candidate explained. "He doesn't think it's real."

"I don't have any idea," Perry continued. "It doesn't matter. He's the President of the United States. He's elected. It's a distractive issue."

Trump briefly considered running for president in the Spring. He gained considerable media attention by questioning whether Obama was an natural born citizen and eligible to be President of the United States.

Many of the so-called “birthers” believe there is persuasive evidence that Obama was born in Kenya in 1961 and that his birth certificate was faked in order to make him eligible for the presidency.

In an attempt to quiet the conspiracies, Obama released his long-form birth certificate in late April. It confirmed what his other birth certificate released in 2008 said: the president was born in Honolulu, Hawaii on August 4, 1961.

Watch this video from CNBC, broadcast Oct. 25, 2011.

With earlier reporting by Eric W. Dolan