The bill, which would allow religious leaders to govern marriage contracts and wed children, has prompted public demonstrations by women's rights groups and activists in Iraq.
"The boys and girls of Iraq, already victims of grave violations resulting from years of conflict, are now at risk of being deprived of their childhood," Virginia Gamba, UN children and armed conflict envoy, said in a statement.
Cops save 12-year-old from child marriage
"The government of Iraq must take all necessary actions to protect every child by preventing the adoption of policies that can harm children already exposed to armed conflict," she said.
About one in five girls is married before turning 18 in Iraq, where the legal age for marriage is 18 but girls can wed at 15 with parental consent, according to the United Nations' children's agency (UNICEF) and global charity Girls Not Brides.
Around the world, 15 million girls are married before the age of 18 every year, according to Girls Not Brides.
Despite law, child marriage continues unabated in Sindh
The proposal in Iraq, which opponents say could allow the marriage of children as young as 9 or at puberty in some religious sects, has been approved in principle by the Council of Representatives, the country's legislature, local media says.
The draft amendment to Iraq's personal status law could fuel infighting as the nation deals with the scars of Islamic State and conflict-related sexual violence, said Gamba and Pramila Patten, UN special envoy on sexual violence in conflict.
They called for a law setting a minimum age for marriage of 18.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ