On the same day, President Bush said that the United States will work for the return of captive Americans in Iraq, but will not submit to terrorist tactics. "We, of course, don't pay ransom for any hostages," Mr. Bush said.
"What we will do, of course, is use our intelligence-gathering to see if we can't help locate them," Mr. Bush said.
The video, the authenticity of which could not be immediately confirmed, also bore the logo of the Islamic Army in Iraq and showed a U.S. passport and an identification card that identified him as Ronald Schulz, CBS News correspondent Kimberly Dozier reports. The video says that unless all Iraqi prisoners are released,
If true, the man would become the second American taken hostage in the last two weeks. A U.S. citizen was among four peace activists taken hostage on Nov. 27 by a group calling itself the Swords of Righteousness. Two Canadians and a Briton were also part of that group.
A French engineer was taken hostage in Baghdad on Monday and a German aid worker was abducted near Mosul on Nov. 26.
Police Maj. Falah al-Mohammadawi said he didn't have any additional information Tuesday about the kidnapping of the French engineer, Bernard Planche, but that the Interior Ministry had distributed Planche's photo to all the checkpoints around Baghdad.
In London, British Foreign Secretary Jack Straw on Monday encouraged the kidnappers of the Briton to make contact, saying "we stand ready to hear what they have to say."
The British Broadcasting Corp. cited a Western diplomat in Baghdad as saying direct contact had been made with the hostage-takers. It did not identify the diplomat.
Straw, however, underlined the British government's refusal to negotiate with kidnappers or pay ransom.
There is no evidence the kidnappings were coordinated, and those responsible for abducting the German aid worker and four Christian peace activists claim to represent different groups. But the incidents do seem timed to coincide with Saddam's trial or the Dec. 15 elections.
Christian Peacemaker Teams issued another statement Tuesday, appealing to the kidnappers to release the four activists.
"As you can see by the statements of support from our friends in Iraq and all over the world, we work for those who are oppressed," the group said. "We also condemn our own governments for their actions in Iraq."