U.S. Defense Secretary Leon Panetta has condemned a video that appears to show U.S. Marines urinating on the bodies of dead Taliban fighters.

Panetta said Thursday he has seen the video, calling it “utterly deplorable.” He vowed those responsible will be held fully accountable.

The defense secretary also ordered the U.S. Marine Corps and the head of the NATO security force in Afghanistan to investigate the video, which appears to show Marines in combat uniforms urinating on three corpses.

In the video, one person suspected of committing the act says “have a nice day,” referring to one of the dead.

ISAF called the act “disrespectful” and said it tarnishes the high moral standards expected of coalition forces.

Afghan President Hamid Karzai said his government is “deeply disturbed” by the video, and that the actions depicted amount to desecration of the Afghans' bodies. He called the alleged act “simply inhuman.”

The Pentagon said it has no reason to doubt the authenticity of the footage.

Meanwhile, a Taliban spokesman said while the video is “shocking,” he did not think it would derail peace talks with the United States. He said those talks are at a “preliminary stage.”

The Marines in the video are apparently are no longer serving in Afghanistan.