Aid worker Margaret Hassan said on the tape, "Please help me, please help me,"
"This might be my last hour."
Hassan asked British Prime Minister Tony Blair to withdraw troops from Baghdad, just one day after Blair's government agreed to redeploy troops from the south to Baghdad. In doing so, more U.S. troops would be freed up to fight insurgents.
Hassan was videotaped only from the shoulders up, appearing alone against a wall. No group has taken responsibility for her abduction, which occurred Tuesday in Baghdad while she was heading to CARE's office in western Baghdad.
No demands were given for Hassan's release.
In the video Hassan referred to Kenneth Bigely, a British hostage who was beheaded earlier this month.
"That's why people like Mr. Bigely and myself are being caught. And maybe we will die like Mr. Bigely. Please, please, I beg of you," the aid worker said as she asked Britons to call for their troops to be removed from Iraq.
The Irish-British-Iraqi national is the highest profile victim in a recent kidnapping campaign in Iraq.
Hassan has lived in Iraq for 30 years, working to distribute medicine and food, and is married to an Iraqi. She began her work for CARE International in 1991 after the Gulf War when it began there -- its programs focused on rebuilding water sanitation systems, hospitals and clinics, the Associated Press reported.
Friday's tape was the second time Hassan has appeared on video. Tuesday the kidnapped CARE official was shown in a silent video sitting on a sofa, and a close-up of her identification cards was shown.
Hassan decided last year to stay in Iraq even after nearly all other international aid groups decided to leave Baghdad.
More than 150 foreigners have been kidnapped in Iraq since April, according to The Washington Post. Out of the 150 kidnapped, about 35 have been killed. Seven women, not including Hassan, have been abducted and all were released.
Also Friday U.S. military launched another raid targeting insurgents in the Sunni town of Fallujah, while U.S. troops used loudspeakers to tell residents to hand in wanted militants, Reuters reported.
U.S. forces have intensified pressure in Fallujah in the past week, while it aims to drive out militants led by Abu Musab al-Zarqawi.
A car bomb exploded near an armored vehicle in the northern Iraqi city of Mosul, wounding five U.S. soldiers, the AP reported.