The United States has condemned a video that appears to show U.S. Marines urinating on the bodies of dead Taliban fighters.

Defense Secretary Leon Panetta said Thursday the video is “utterly deplorable.” He vowed those responsible will be held fully accountable.

Panetta ordered the U.S. Marine Corps and the head of the NATO security force in Afghanistan to investigate the video.

The defense secretary spoke by phone Thursday with Afghan President Hamid Karzai and affirmed there will be a serious probe into the incident.

Secretary of State Hillary Clinton echoed Panetta's condemnation of the act, saying it is inconsistent with American values and the standards of behavior expected from U.S. military personnel.

Mr. 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 act “simply inhuman.”

A Taliban spokesman said while the video is “shocking,” he did not think it would derail peace talks with the United States.

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

U.S. military officials said Thursday the Marine Corps have identified troops in the video, but no names were released.

The NATO security force in Afghanistan called the act “disrespectful” and said it tarnishes the high moral standards expected of coalition forces.

The commandant of the U.S. Marine Corps said he has requested the Marines and U.S. Navy conduct separate investigations into the video. He said the Marine Corps remains committed to upholding the Geneva Convention, the laws of war and its own core values.

The video appears to show Marines in combat uniforms urinating on three corpses. In the footage, one person suspected of committing the act says “have a nice day,” referring to one of the dead.

The U.S. Marine Corps has not commented on the identities or units of those involved. The Marines in the video are apparently no longer serving in Afghanistan.