US Secretary of State Hillary Clinton, a strong advocate of women's rights, has raised Saudi Arabia's ban on women driving with the kingdom's foreign minister, the State Department said.

Clinton spoke to Saudi Foreign Minister Prince Saud Al-Faisal on Friday to discuss a range of regional issues, State Department spokesperson Victoria Nuland said.   

"In that conversation they talked about Yemen, they talked about Syria and the subject of driving did come up," Nuland said.   

Rights groups have publicly pressed Clinton to weigh in on Saudi Arabia's driving ban, which has been publicly challenged in recent weeks by Saudi women who have risked arrest to get behind the wheel.

Nuland declined to give further details of Clinton's conversation with Prince Saud but said her relatively soft approach to the issue did not mean Clinton viewed the issue as unimportant.

"I think she is making a judgment on how best to support universal rights for women," Nuland said. "There are times when it makes sense to do so publicly and there are times for quiet diplomacy.   

"The secretary has been engaged, as have others, in quiet diplomacy on this subject." -Reuters