KABUL, Afghanistan, Sept. 2 (Xinhua) -- U.S. Defense Secretary Gates arrived in Afghanistan's capital Kabul on Thursday for an unannounced visit.
He is expected to meet with President Hamid Karzai and top U.S. and NATO-led troops commander Gen. David Petraeus.
Gates flew to Kabul from Baghdad, where he participated in ceremonies marking the formal close of the U.S. combat mission in Iraq.
