President Obama used a speech before the Clinton Global Initiative today to outline new steps his administration is taking to stop human trafficking, which he said "must be called by its true name, modern slavery."

The president said he does not use the term "slavery" lightly, but that there's "no denying the awful reality."

"When a man desperate for work finds himself in a factory or on a fishing boat or in a field, working, toiling for little or no pay and beaten if he tries to escape, that is slavery," he said.

"When a little girl is sold by her impoverished family - girls my daughters' age - runs away from home, or is lured by the false promise of a better life and then imprisoned in a brothel and tortured if she resists, that's slavery," he continued.

"It is barbaric and it is evil, and it has no place in a civilized world," he said.

The president highlighted his administration's efforts to help the more than 20 million victims of human trafficking around the world, saying more nations have passed and are enforcing anti-trafficking laws.

"But for all the progress that we've made, the bitter truth is that trafficking also goes on right here in the United States," he said. "As president, I directed my administration to step up our efforts, and we have… because we can't ask other nations to do what we are not doing ourselves."

Obama said the United States is devoting more resources to identifying trafficking networks and strengthening worker protections in an effort to stop exploitation.

Timed to today's speech, the president signed a new executive order intended to enhance protections against human trafficking in government contracting.

"We're making clear that American tax dollars must never, ever be used to support the trafficking of human beings. We will have zero tolerance. We mean what we say. We will enforce it," he said.

The president's speech, which came just hours after rival Mitt Romney addressed the same forum, brought him together with former president Clinton for the first time since the Democratic National Convention. Introducing the president, Clinton joked that "if you're an American citizen and you introduce the president, you're supposed to say, the president of the United States and shut up."

"I just want to make one comment about this. I want to finish that speech I started in Charlotte," he said to applause and laughter from the audience.