London, Rabi'II 20, 1433, Mar 13, 2012, SPA - U.S. President Barack Obama and British Prime Minister David Cameron will open official talks later today. The talks are expected to focus on Afghanistan, Iran's nuclear program and the Syrian crisis. Cameron is heading to the United States for a three-day visit focused on current and looming foreign policy challenges, seeking to pin down details of the planned withdrawal of international forces from Afghanistan by the end of 2014, according to foreign news agencies' reports. --SPA 13:54 LOCAL TIME 10:54 GMT www.spa.gov.sa/979129