Police distributed videos of the arrest and public interrogation to the media on Monday, a day after they were made.
The girl gave her first name as Rania and said she was born in 1993. She appeared confused in the questioning, giving conflicting answers about whether she knew two women who put the vest packed with 33 pounds of explosives on her.
In the video of the arrest, a policeman standing next to the teenager could be heard saying that when she was picked up, she was initially unable to talk because she had been given drugs.
She denied under questioning that she planned to carry out an attack, saying she had been instructed to remove the vest when she got home.
The arrest heightened concern about a rise in suicide bombings by women. The number of female bombers has more than tripled from eight in 2007 to 29 this year, according to U.S. military officials.
The arrest video begins with the girl standing on a street in the city of Baqouba, capital of the volatile province of Diyala and a stronghold of al Qaeda in Iraq. She is shown with her arms behind her back, cuffed to a metal structure with police surrounding her.
At some point, a policeman partially removes her brightly colored, flowered robe and subsequent frames show her with her arms bare and chest partially exposed, wearing a white vest. Another picture shows a two-sided vest with pockets in both front and back filled with explosives.
The girl is then shown standing in a room, wrapped in a black cloak, her dark brown hair dyed a lighter shade and surrounded by several police officers.
During the public interrogation, reporters from local and foreign media stood behind cameras but did not ask the suspect any questions.
In the interrogation, she gives conflicting answers about whether she knew the women who gave her the vest.
"I swear to Allah that I do not know them. They were strangers," she is heard saying initially. But later she says "one of the women's names was maybe Fadhila and the other was called Widad."
When pressed about whether she knew the woman she then replied: "Yes."
"No, no, they put it on me and told me to take it off at home," she said. "They did not tell me to blow myself up."
A policeman then asks: "If so, why didn't you disconnect" the detonator?
The girl says: "I did not disconnect it (because) maybe it fell off me."
The circumstances of the girl's arrest remained unclear. U.S. officials said she had turned herself in, while local police said she was caught after arousing suspicion.
Her exchange with police offered a rare glimpse at a teenager allegedly recruited by insurgents.
An Iraqi police officer said the girl came from a family of al Qaeda in Iraq supporters in Baqouba and that her father had carried out a suicide bombing. The officer said a relative is suspected of having recruited her. He spoke on condition of anonymity because he was not authorized to release the information.
He said the girl led them back to the area of Baqouba where she was given the explosives, and that they found a second bomb belt there. But that the apartment was empty. He said the girl's mother and sister were arrested.
Some female bombers may have been motivated by revenge. U.S. commanders believe al Qaeda in Iraq is increasingly seeking to exploit women who are unable to deal with the grief of losing husbands, children and others to the violence.
Many Iraqi women wear long robes, ideal for covering bulky suicide vests, and Iraqi policemen hesitate to pat them down at checkpoints because of cultural taboos.
The military said that in Diyala, some 200 female volunteers recruited by the U.S.-backed group Daughters of Iraq are helping search women at checkpoints. Diyala has been one of the most violent areas in Iraq, even as the rest of the country witnessed a significant drop in attacks.
Prime Minister Demands U.S. Withdrawal Timetable, Rejects Immunity
Iraqi Prime Minister Nouri al-Maliki says there can be no security agreement with the United Statesfor the withdrawal of American troops.
Al-Maliki also says that unless some clauses in the draft agreement under discussion are changed, it will be "difficult" for the pact to be adopted.
He did not identify all those clauses.
But the prime minister told tribal leaders Monday that he cannot grant "open immunity" to Iraqis or foreigners because that would violate the "sanctity of Iraqi blood."
Baghdad and Washington are negotiating an agreement on the future of U.S. troops in Iraq.
Al-Maliki aides say Iraq insists on 2011 as the target date for the withdrawal of the last U.S. soldier.