DOHA // The US secretary of state, Hillary Clinton, is beginning a visit to two key US allies in the Gulf. Mrs Clinton arrived today in Qatar, where she is holding talks with top government leaders and speaking at an international conference called the US-Islamic World Forum. President Barack Obama addressed the forum by video on yesterday, announcing that he is appointing a special envoy to the Organiaation of the Islamic Conference. Mrs Clinton also is scheduled to visit Saudi Arabia to meet with King Abdullah and to hold a town hall-style meeting with students at a Saudi women's college. In both countries Mrs Clinton plans to raise the issue of how to contain Iran's nuclear program, which is of great worry among the Gulf Arab states.