United States refused to criticize Saudi Arabia for doubling the corporal punishment sentence imposed on a gang rape victim for speaking out against the 90 lashes and six months in prison meted out to her earlier.

State Department spokesman Sean McCormack said on Monday that it was nothing more than "part of a judicial procedure overseas in the courts of a sovereign country."

McCormack added that "most would find this relatively astonishing," but did not reply when reporters asked him whether the United States was "astonished" by the decision.

"I can't get involved in specific court cases in Saudi Arabia dealing with its own citizens," the spokesman said.

Questioned again on Tuesday about the broader issue of reforms in Saudi Arabia, McCormack said Saudis had the right to "make decisions about very basic societal issues and what their norms are. It's going to vary from country to country."

"We're not going to try to dictate social norms to various countries," he said.

A court in Saudi Arabia's eastern province of Qatif increased the number of lashes imposed on the rape victim to 200 because the 19-year-old "attempted to aggravate and influence the judiciary through the media".

The young woman, who is married, said she had met with a male acquaintance who had promised to give her back an old photograph of herself, when a gang of seven men attacked and raped both of them, multiple times, according to Human Rights Watch.

The court sentenced the woman to six months in prison and 90 lashes for "illegal mingling" with a male who was not a relative.

Any contact between unmarried individuals of the opposite sex is a criminal offense in Saudi Arabia.

The perpetrators were only convicted of kidnapping, apparently because prosecutors could not prove rape because the judges reportedly ignored evidence from a mobile phone video in which the attackers recorded the assault, the human rights group reported.