U.S. soldiers prepare for a joint patrol with Iraqi police in the city of Kirkuk, 250 km (155 miles) north of Baghdad September 1, 2010. Roughly 50,000 U.S. soldiers still in Iraq are moving to an advisory role in which they will train and support Iraq's army and police. U.S. President Barack Obama has promised to pull all U.S. troops out of Iraq by the end of 2011. REUTERS/Ako Rasheed (IRAQ - Tags: CONFLICT POLITICS MILITARY)