The Arabic television station Al-Jazeera television has broadcast a new tape with Irish hostage Ms Margaret Hassan pleading for the release of all female prisoners in Iraq.
Ms Hassan also urged Britain to withdraw troops from Iraq and for CARE International to close its offices.
The video showed Ms Hassan standing in a dimly lit room. "Please don't bring the soldiers to Baghdad... Please, on top of that, please release the women prisoners from prisons," she said.
About 850 British troops, mainly from the Black Watch regiment, are due to deploy in a restive region just south of Baghdad, allowing US troops to reinforce units fighting insurgents in rebel-held Falluja and elsewhere. US forces would spearhead any assault on the Sunni Muslim city, which Iraq's interim government has vowed to retake before nationwide elections planned for January.
The Iraqi government believes pacifying Falluja would help contain relentless suicide car bombings and abductions.
Ms Hassan, who was born in Ireland but has lived in Iraq for over 30 years after moving there from Britain with her Iraqi husband, was taken hostage last week.
Al-Jazeera broadcast a statement from the Taoiseach, Mr Ahern, last week appealing for the release of Ms Hassan. The statement was shown hours after the station broadcast a video of a distressed Ms Hassan pleading for help from the British people to save her life. She also appealed to the British people to pressurise Mr Blair to withdraw troops from Iraq.
Ms Hassan was filmed begging for her life and breaking down in tears. Her captors have not yet identified themselves as a group or issued any demands separate from the video.
Kidnappers have seized scores of foreigners since April in a campaign to try and force US-led troops and foreign workers to leave Iraq. More than 35 hostages have been killed.
The Paris-based aid group Action Contre la Faim said it was withdrawing its staff from Iraq due to security concerns, adding that aid activities by US-led forces made it hard for charities to appear impartial.
A suspected motorcycle bomb attack on a US convoy killed a soldier and wounded another north of Baghdad, the military said. That fatality raised the US combat death to 847 since the start of last year's war to topple Saddam Hussein.
US officials said the Pentagon might increase US forces in Iraq for the election period by delaying the departure of some troops and speeding the arrival of others.
The Iraqi government has vowed to unleash military action unless the people of Falluja hand over foreign militants led by al-Qaeda ally Abu Musab al-Zarqawi, said to operate in the city.
Zarqawi's feared Islamist group threatened yesterday to behead a Japanese hostage unless Tokyo pulls its 550 troops out of Iraq within 48 hours. Japan rejected the demand.
Militants abducted five Japanese civilians in Iraq in April and threatened to kill three unless Japanese troops left. In July, the Philippines withdrew its 50 troops to save a Filipino hostage under a similar death threat.