U.S. Defense Secretary Robert Gates has arrived in Afghanistan for talks with commanders and Afghan President Hamid Karzai.
His unannounced trip comes ahead of a review of U.S. military policy in Afghanistan due for completion next week.
The review will gauge whether last year's surge of an additional 30,000 soldiers to Afghanistan, ordered by U.S. President Barack Obama, in order to train Afghans to take control of their own security is working to suppress the insurgency.
There are now 150,000 coalition forces in Afghanistan, over half of them American.
The United States and its NATO partners agreed last month to begin turning over control to local Afghan authorities in 2011, with a goal of completing the transition by the end of 2014.
compiled from agency reports