Foreign Affairs Minister Dermot Ahern says he is deeply concerned at the kidnapping of Margaret Hassan in Iraq and called for her immediate and unconditional release.
He said he and his officials are ready to contribute in any way they can to help secure this.
Al Jazeera television has broadcast footage of the Irish-born woman working as the head of Care International in Iraq who was kidnapped early today.
Margaret Hassan was seen sitting in a room and looking anxious. No audio could be heard.
The Department of Foreign Affairs has confirmed that she is an Irish citizen. A spokesman said Mrs Hassan was born in Ireland and has lived in Iraq since the early 1970s.
It has also been confirmed that the Department is in contact with her siblings in Ireland.
Mrs Hassan, who has been working for the charity in Iraq for over ten years, was kidnapped in Baghdad at about 7.30am local time.
She has lived in Iraq for more than 30 years, and has dual British and Iraqi nationality.
The station showed close-ups of Mrs Hassan's identification cards and said the video was accompanied by a claim of responsibility from an unnamed Iraqi group.
Four killed in Baghdad mortar attack
Four Iraqi national guards were killed and up to 80 others wounded in a mortar attack on the National Guard’s headquarters north of Baghdad today.
The Iraqi Defence Ministry said the attack occurred this morning at Tarmiya, about 16 miles north of the capital.
Earlier, a US contractor was killed and seven others were wounded in an attack on a US army compound in Baghdad.
The US military said its compound in the centre of the city came under mortar and rocket fire this morning.