The United Nations agreed on Friday that all members should pass and enforce laws banning child marriages, resolving to end a practice that affects about 15 million girls every year.
The committee of the 193-nation General Assembly that deals with human rights adopted by consensus a resolution urging all states to take steps to end "child, early and forced marriage."
There are now more than 700 million women who were married before their 18th birthday, many in conditions of poverty and insecurity, according to U.N. statistics.
Child marriage among girls is most common in south Asia and sub-Saharan Africa. In Niger in West Africa, which has the highest overall rate, 77 percent of women between 20 and 49 were married before the age of 18.
Bangladesh has the most girls who married under 15 and India is home to one third of all child brides worldwide.
Christine Kalamwina, the deputy permanent representative of Zambia, which initiated the resolution with Canada, said child marriage impeded poverty reduction, education, gender equality and women's empowerment, child mortality, maternal health, and combating HIV/AIDS and other diseases.
According to the resolution, early marriage is also a serious threat to the physical and psychological health of girls who are not physically mature enough as it "increases the risk of unintended pregnancy, maternal and newborn mortality and sexually transmitted infections."
The 118 countries that sponsored the resolution included Mali, Ethiopia and the Central African Republic, which are among the 10 countries with the highest rates of child marriage.
The resolution called on states to ensure that marriage is entered into only with the full consent of the intending spouses, was adopted without a vote. The resolution will go to the full General Assembly for formal approval in December.
While supporting the document, the Islamic Republic of Iran and Sudan both expressed concern over a paragraph urging governments to protect the right of girls to have control over their sexuality and implement laws that protect reproductive rights.
General Assembly resolutions are not legally binding, but can increase political pressure on countries.
"This is a firm statement from the international community that child marriage will not be tolerated," Girls Before Brides, a global partnership of over 400 civil society organizations, said in a statement.