the story from cnn....
BAGHDAD, Iraq (CNN) -- An al Qaeda-linked Web site posted video Tuesday of an American man in Iraq speaking briefly before being beheaded by his masked captors.
His captors said the United States refused to exchange him for prisoners in the Abu Ghraib prison. A senior U.S. official told CNN he does not believe that to be true.
The captors also issued a direct statement to President Bush: "The worst is coming and, God willing, the tough days are still to come. You and your soldiers will regret the day that you touched the ground of Iraq."
In the video, a man identifies himself as Nicholas Berg, 26, of Pennsylvania and is shown sitting in an orange jumpsuit in front of five armed, hooded men.
The one standing directly behind Berg reads a statement identifying himself, and then Berg is pushed to the floor.
Berg is heard screaming as his throat is cut. One of the captors then holds up his severed head.
"For the mothers and wives of American soldiers, we tell you that we offered the U.S. administration to exchange this hostage for some of the detainees in Abu Ghraib and they refused," the hooded man standing behind the American said just before the killing.
"Coffins will be arriving to you one after the other, slaughtered just like this."
White House spokesman Scott McClellan told reporters, "this shows the true nature of the enemies of freedom. They have no regard for the lives of innocent men, women and children."
At the Pentagon, officials confirmed that a body found in Iraq by an Army patrol is the person shown in the beheading video. Earlier, the State Department had identified the body as that of Berg.
The Web site said the killing had been carried out by Abu Musab al-Zarqawi, the leader of an Islamist terrorist group that has claimed responsibility for numerous attacks on coalition forces in Iraq.
The voice on the tape could not be verified as that of al-Zarqawi. CNN staffers familiar with al-Zarqawi's voice said the voice on the tape did not sound like him.
The Web site also published the text of the statement attributed to al-Zarqawi.
In the statement, the captors refer to the abuse of Iraqi prisoners at the hands of U.S. military personnel, saying the "picture of dishonor and the news of Satanic assault on the people of Islamic men and women" will not be tolerated.
"Where is the compassion, where is the anger for God's religion, and where is the protection for Muslims' pride in the crusaders' jails?" the man says.
"We tell you the pride of all Muslim men and women in Abu Ghraib and other jails is worth blood and souls."
Berg was not a soldier or a civilian employee of the Pentagon, the State Department said.
Outside the family home Tuesday in suburban Philadelphia, Bruce Hauser, a neighbor and family spokesman, said Berg owned a company that cleaned and repaired communications towers in Iraq.
Hauser said Berg's family learned about his death Monday and is devastated by the news. The family has asked the State Department to release the body as soon as possible, he said.
Berg's family told The Associated Press that they knew he had been decapitated but weren't aware of the details.
Nicholas Berg was due to leave Iraq on March 30, his family said.
"I knew he was decapitated before," Michael Berg told the AP. "That manner is preferable to a long and torturous death. But I didn't want it to become public."
Suzanne Berg said her son was in Iraq as an independent businessman.
"He had this idea that he could help rebuild the infrastructure," she told the AP.
One government official said Berg had earlier been arrested by Iraqi police in a sweep and detained by coalition authorities. Those authorities contacted the FBI, which interviewed Berg, the source said.
Berg was released when authorities realized he was in Iraq legally, the source said. He was in the process of leaving Iraq when he was taken captive by insurgents.
The FBI confirmed that agents also interviewed Berg's parents about why he was in Iraq.
"The agency had been asked to interview the parents regarding Mr. Berg's purpose in Iraq," FBI spokeswoman Jerri Williams said without elaborating.
In early April, Berg's parents filed suit against Defense Secretary Donald Rumsfeld, saying their son was being held by the U.S. military without merit. However, just days after it was filed, the suit was declared moot.
Rep. Jim Gerlach, who represents Berg's hometown, said he had spoken with the family and they are "very, very much emotionally traumatized by this death. Yet at the same time, they are very strong and they are very composed."
He said the family also wants to "find out a lot more information" about what happened between the time Berg was released by authorities and when he was taken hostage.
"They are very interested in finding out more about those circumstances," Gerlach told CNN.