video transcript

A person in an Afghan military uniform turns his weapon on U.S. and Afghan forces killing two American soldiers in the eastern province of Wardak. The attack took place as a deadline expired for U.S. special forces to leave Wardak -- and after Afghan President Hamid Karzai accused U.S. troops working alongside Afghan accomplices ... overseeing torture and killings in the area. Incidents involving Afghan security forces turning their weapons on the NATO-led forces have increased sharply over the past year. The attack came shortly after U.S. Secretary of Defense Chuck Hagel, left Afghanistan after his first trip overseas as defense secretary. Karzai also accused the US of colluding with the Taliban to prolong the U.S. military presence there. White House spokesman Jay Carney: (SOUNDBITE) (English) U.S. WHITE HOUSE SPOKESMAN JAY CARNEY SAYING: "Any suggestion the United States is colluding with the Taliban is categorically false. Secretary Hagel addressed these questions directly with President Karzai in their meeting." Hagel's trip failed to answer the big question about America's evolving exit strategy from the unpopular conflict that has cost billions of dollars and thousands of lives.