Two days after Facebook CEO Mark Zuckerberg offered his first public comments about immigration reform since launching a political action committee devoted to the issue in April, the group, FWD.us, is taking to the television airwaves with a six-figure ad buy aimed at persuading on-the-fence members of Congress to back reform, ABC News has learned.

Timed to coincide with the month-long Congressional recess - a prelude to a contentious fall debate over immigration issues on Capitol Hill - the new ad features Alejandro Morales, an undocumented immigrant who came to the United States from Mexico when he was seven months old. Morales attended the Marine Math and Science Academy in Chicago and joined the junior ROTC. However, because of his immigration status, he says he is barred from serving.

FWD.us/YouTube

"I want to be a U.S. citizen. I want to be a Marine. I'm going to be a Marine because I care. I care about this country. I care about those around me. I care about my family, my neighbors," Morales says in the one-minute commercial. "I do want to give back. I believe 100 percent in what this country stands for. Let me earn it. Let me serve."

The ad will be backed up by a "mid-six-figure ad buy," according to a source close to the group. It will run starting Wednesday on cable channels and online across the country. It will also air on local stations in Arizona, Florida, Georgia, Illinois, New Mexico, Texas and Washington, D.C.

"We are running this ad to put a very human face on our broken immigration system," FWD.us president and founder Joe Green said in a statement. "While Alejandro's story is powerful, it is not unique. Undocumented immigrants already contributing to our communities want to be recognized as Americans, and want the opportunity to continue to serve our country and contribute to its success - as members of the armed forces, as teachers, scientists, entrepreneurs and business owners, and in many other capacities.

"We hope that by showing Americans the cost of this broken system and the contributions people like Alejandro are already making, they will join with us in supporting real reform," the statement added.

Green and Zuckerberg both spoke Monday night at the West Coast screening of the film "Documented," which chronicles the struggles of immigration reform activist Jose Antonio Vargas, who is an undocumented immigrant from the Philippines and a former journalist. Those who attended the screening included technology executives such as Facebook's Sheryl Sandberg, elected officials including House Democratic Leader Nancy Pelosi, reporters, and some of the immigrants whose lives would change if immigration reform makes its way out of Congress.

On Wednesday FWD.us also hosted a roundtable immigration discussion with Rep. Jeff Denham, R-Calif., a lawmaker representing California's Central Valley, the home of many immigrants who work in the state's agricultural sector.

In an e-mail message sent last week by FWD.us, Green urged activists into action this month.

"August recess is no time for us to rest easy," he wrote. "In fact, August will be a critical month for immigration reform - the most critical month yet - and we need your help to move reform forward."

Green encouraged supporters to lobby their members of Congress before they head back to Washington to continue negotiations on various immigration reform proposals, imploring volunteers to "speak up on the phone, on social media, and with your friends and family."'

FWD.us drew criticism from liberals earlier this year for other ads it has backed, but Zuckerberg did not address the detractors during his remarks in San Francisco on Monday. Instead, he told a brief, personal story about what compelled him to start the organization in the first place.

"These are issues that don't just touch our part of the industry, but really touch the whole country," Zuckerberg said, "and touch what is right for us to do as a people."