Actor Ashton Kutcher posed on the red carpet before the premiere of the movie 'Jobs' in New York, Aug. 7, 2013. Reuters

Ashton Kutcher, a star of the long-running "That 70's Show" and a litany of romantic comedies, testified before the Senate Foreign Relations Committee Wednesday along with Elisa Massimino, president and chief executive of the New York-based nonprofit Human Rights First, as part of a campaign against human trafficking.

The session got off to a lighthearted start, with Arizona Sen. John McCain remarking that Kutcher was "better looking in the movies." The 39-year-old actor responded to the former Republican presidential candidate by blowing a kiss.

The mood in the Senate chamber quickly became more emotional, however, as discussion turned away from Kutcher's looks and toward the topic he and Massimino had come to spotlight.

“I’ve seen video content of a child that’s the same age as mine being raped by an American man who was a sex tourist in Cambodia, and this child was so conditioned by her environment that she thought she was engaging in play,” Kutcher told the committee in an impassioned testimony. “I’ve been on the other end of a phone call from my team, asking for my help because we had received a call from the Department of Homeland Security, telling us that a 7-year-old girl was being sexually abused and that content was being spread around the dark web and she had been being abused and they’d watched her for three years, and they could not find the perpetrator, asking us for help. We were the last line of defense—an actor and his foundation were the potential last line of defense. That’s my day job, and I’m sticking to it.”

The full footage of the hearing, titled "Ending Modern Slavery: Building On Success," is available on C-SPAN.

Aside from his acting career, Kutcher co-founded the organization Thorn: Digital Defenders of Children, formerly known as the DNA Foundation, in 2009 with his ex-wife, actress Demi Moore. The couple has continued to grow and promote their organization in the years since the split, with a specific focus on the internet's role in sex trafficking and exploitation of minors.

"For the past three years we have focused our work broadly on combatting child sex trafficking. It has become crystal clear in our efforts that technology plays an increasingly large role in this crime and in the sexual exploitation of children overall," Moore and Kutcher said in a joint statement to People Magazine in 2012. "We believe that the technology-driven aspect of these crimes demands its own attention and investment."