Facebook founder and CEO Mark Zuckerberg said Wednesday that immigration reform would help Silicon Valley but that's not why he's lobbying Congress for a bill.

Improving access to visas for high-skilled immigrants is a laudable goal, Zuckerberg said, and one his tech brethren would happily exploit to fill engineering openings. But the 29-year-old billionaire said he is more concerned about the nation's 11 million illegal immigrants, particularly the children.

"Often times people talk about high-skill and comprehensive immigration reform as if they're different things," Zuckerberg said. "That student is going to be the entrepreneur of tomorrow. And this is a big deal."

Zuckerberg is in Washington this week meeting with House and Senate leaders on Capitol Hill about immigration. Wednesday afternoon, donning his signature hoodie and jeans, the social media pioneer spoke to a standing-room only crowd of business leaders and reporters for 45 minutes at the Newseum in a discussion hosted by the Atlantic.

While a wide range of topics were addressed, from digital privacy to how Zuckerberg occupies his free time (with work), immigration reform dominated much of the substantive discussion.

Zuckerberg said he was pushed into the debate, and later into creating FWD.us, a political action group, by teaching an after-school entrepreneur class to youths in East Menlo Park, Calif.

"It was a really rewarding experience, but the thing I took away from it is one day after school, I asked the students how they were thinking about going to college and my top student raised his hand and said, 'I don't know if I'm going to be able to go to college because I'm undocumented,'" Zuckerberg recalled. "And that just blew my mind."

Zuckerberg, whose personal wealth reaches $3.8 billion, has only recently entered the political conversation. He held fundraisers for both New Jersey Republican Gov. Chris Christie and the state's Democratic U.S. Senate candidate Cory Booker. He said he's not a Democrat or a Republican, but rather "pro-knowledge economy."

His foray into politics with FWD.us has drawn mixed reviews for its traditional political approach and the conventional ads it ran to pressure lawmakers, but Zuckerberg insists his concept is novel because he's trying to work with both sides of the aisle.

"There's been a lot to debug in terms of making this work," Zuckerberg said. "One of the things that's been interesting and challenging is we tried to get senior folks of both parties to come together and there were interesting realities of that that I was kind of shocked about."

Zuckerberg also backed up his recent criticism of the National Security Agency's spying program, saying it has hurt the trust between online users and Facebook, and that the government botched explaining or justifying its use of surveillance on citizens.

"Some of the government statements have been profoundly unhelpful," Zuckerberg said. "'Oh, we only spy on non-Americans.' Gee, thanks. We're trying to be an international service."

Facebook is reaching its 10th birthday and as the site has matured, so has Zuckerberg. He is more comfortable on stage than the sweaty, nervous kid who became the face of a generation a decade ago.

Perhaps that's why Zuckerberg has seen an opening to enter the political arena now that Facebook has secured itself as a major player. He said his wife told him not to be the type of individual who donates money but doesn't put any skin in the game.

And Zuckerberg willingly admits that Facebook may have lost its shine among the college-age students who once made up nearly all its users. Grandparents are liking photos on Facebook, and its founder, once immortalized in the movie "The Social Network," is now debating immigration reform. But Zuckerberg said that all comes with growth.

"People assume we're trying to be cool. That's not my goal," Zuckerberg said with a laugh. "I'm the least cool person there is."