Tahsin Ali Hassan said on Thursday: "I am hopeful insha Allah (God willing).
"I do not know the party that kidnapped her but they should know that my wife has given a lot to the Iraqi people and that she is Iraqi."
Margaret Hassan, 59, the director of relief agency Care International in Iraq and a Briton born in Ireland who is also a naturalised Iraqi citizen, was taken hostage on Tuesday as she drove to her office in western Baghdad.
Hassan said he did not know if his wife, who never converted to Islam, was abducted for financial or political motives. The identity of her kidnappers is not known.
"If it was for political reasons, I need to say that Care is a humanitarian organisation that has nothing to do with politics. It collects funds from donor countries to help Iraqis," he said.
His wife is employed through Care Australia's Canberra headquarters which runs the group's Iraq activities. The agency has since announced it is suspending its Iraq operations.
Margaret Hassan, who speaks fluent Arabic and lived nearly half her life in Iraq, did not consider herself a foreigner despite the recent kidnappings and killings of foreigners supporting the US, her husband said."But I warned her that she is a foreigner in the eyes of Iraqis," he added.
Tahsin Ali Hassan says his wife
served the Iraqi people for years
At the time of her kidnapping she was travelling with a guard and driver, he said.
He said they were stopped by four to five men, one of whom was in Iraqi police uniform, according to the driver, who along with the guard was injured in a brief struggle with the kidnappers.
His wife was an outspoken opponent of the sweeping United Nations sanctions imposed on Iraq for more than a decade in the wake of Iraq's invasion of Kuwait.
In January 2003, on the eve of the US-led invasion of Iraq, she travelled to New York and spent a week briefing UN Security Council members and UN agencies on the dire humanitarian consequences of military action.
Australia's Foreign Minister Alexander Downer said on Thursday his country would not pay a ransom or withdraw its 300-troop contingent in Iraq to secure her freedom.