U.S. President Barack Obama and Vice President Joe Biden, who have long talked about the need to curb sexual assault at universities, got some help on Friday from the people many young adults actually listen to: celebrities and athletes.

In its latest effort to help college campuses confront the issue, the White House is relying on a combination of the National Collegiate Athletic Association, social media and star power to spread its message aimed at preventing and coping with such assaults.

Television actors Jon Hamm and Kerry Washington, hip-hop artist Common and NBA basketball player Kevin Love are among those promoting the public awareness campaign, called "It's On Us."

At a star-studded event at the White House's East Room, Obama called rape and sexual assaults "unacceptable" and asked coaches, teachers and bystanders - especially men - to step up to prevent such violence.

"It's not just OK to intervene, it is your responsibility," he said.

The celebrities are featured in videos set to air at college sporting events and across the Internet, the White House said. Companies including videogame maker Electronic Arts Inc and media giant Viacom Inc are also on board to spread the message through Facebook, Twitter and cable television.

Almost one in five women have been victims of sexual assault, according to the U.S. Centers for Disease Control and Prevention. Among those, nearly 40 percent were first assaulted between the ages 18 and 24. In comparison, one in 71 men have reported being raped at some point in their lives, CDC data showed.

The campaign comes as the National Football League grapples with a series of alleged assaults by players. The furor has touched college sports as well, with Florida State University this week benching its top quarterback - for half a game - after he shouted an obscene sexual phrase.

"There's no doubt that colleges and universities need to step up their game," said Biden, who as a senator successfully championed the Violence Against Women Act that celebrated its 20th anniversary this month.

On Friday, thousands of Twitter posts began circulating from the stars involved, retweeted by their fans. "Join the fight+help stop sexual assault," Washington wrote.

One video on the campaign website includes actor Mayim Bialik, comedian Joel McHale, and musician Questlove. Biden and Obama also speak at the end of the clip.

By Susan Heavey

(Editing by Doina Chiacu, G Crosse and Mohammad Zargham)