Dana White restrains Anderson Silva

Middleweight champion Anderson Silva had to be restrained from hitting contender Chael Sonnen as the two prepared to pose for pictures at a media event promoting UFC 148 in Las Vegas on Tuesday.

Still fuming from ongoing verbal taunts Sonnen has directed at him for more than two years, Silva walked quickly toward the man he will face Saturday night in their upcoming title bout and the two began to bump chests.

The more-aggressive Silva moved Sonnen backward, forcing UFC president Dana White to restrain Silva, who had his fists clinched. White then instructed Sonnen to leave the stage.

The incident comes one week after Silva vowed during a conference call to inflict serious bodily harm on Sonnen.

The two fought for Silva's title in August 2010. Sonnen dominated the fight for more than four rounds before getting caught in a triangle armbar at 3:10 of the fifth round.

Despite nearly losing his long-held title, Brazil's Silva offered his reasons Tuesday for not wanting to face the American a second time.

"The comments he made about my wife, the comments he made about my country were very disrespectful, not only to me but also to the country and also the UFC," Silva said. "We're very elite top athletes and we shouldn't be talking like that about each other.

"Chael tested positive for steroids, he offended a nation, he's been charged with a crime. How can you take anything this guy says for real? This guy is ridiculous."

Sonnen pled guilty to one count of money laundering in January 2011. According to the U.S. Attorney's Office for the District of Oregon, the fighter was involved in a mortgage-related fraud.

He received two years' probation and a $10,000 fine.

Sonnen was suspended for one year by the California State Athletic Commission in 2010 for elevated testosterone levels after his first fight with Silva.

In May, the Nevada State Athletic Commission granted Sonnen a conditional therapeutic use exemption for testosterone replacement therapy, applicable to his upcoming rematch with Silva.

After his Oct. 8 win over Brian Stann at UFC 136, Sonnen returned his attention to Silva during a postfight interview. His comment was directed at Silva's wife.

"You tell Anderson Silva I'm coming over and I'm kicking down his back door and patting his little lady on the (butt), and I'm telling her to make me a steak, medium-rare, just how I like it," Sonnen said.

On Tuesday, Sonnen brushed off Silva's remarks and vowed to leave the rematch victorious.

"All I can tell you is that Chael of today can beat up Chael of two years ago, and Chael two years ago stomped this bum," Sonnen said.