"If someone wants to poke fun at me, that's OK," Huntsman said. "What I object to is bringing forward pictures and videos of my adopted daughters and suggesting there's something sinister there."

He called the video, posted by a group backing GOP rival Ron Paul, "stupid" and "political campaign nonsense."

The video includes footage of Huntsman, a former US envoy to China, speaking Mandarin and holding his adopted Chinese-origin daughter 12-year-old Gracie.

There is also an image of him holding another daughter, Asha, who was adopted from India and is now 6. Both are sporting bindi in the picture.

The Huntsmans have seven children.

Meanwhile, a Hindu American group also strongly condemned the advertisement, as the ad criticises Huntsman for raising his adopted Indian daughter in her native Hindu faith.

"This deplorable ad is blatantly racist and religiously intolerant, and crosses all lines of acceptable political discourse," Hindu American Foundation managing director Suhag Shukla said in a statement.

"Instead of vilifying Governor Huntsman, he should be applauded for being open minded enough to raise his adopted daughter as a Hindu," Shukla said.