NATO Secretary-General Anders Fogh Rasmussen is condemning published photos that purport to show U.S. troops posing with the bodies of Afghan militants.
He says he hopes it is an isolated case, and he promised a thorough investigation. The pictures published Wednesday in the Los Angeles Times follow similar instances of misconduct this year.
Rasmussen told reporters at NATO headquarters that the pictures "don't in any way represent the principles and values that are the basis for our mission in Afghanistan."
He says he hopes there will be no spillover of blame onto other NATO troops.
The United States has the largest number of forces under the NATO-led coalition in Afghanistan.