South Africa's Anglican Archbishop is working to end child marriages.

Archbishop Desmond Tutu was in the United States last week to promote a campaign to end the practice of child marriages in the developing world by 2030.

Tutu, 81, chairs the Elders, an international human rights group that established a worldwide campaign called Girls Not Brides: The Global Partnership to End Child Marriage.

According the U.N. Population Fund, about 37,000 girls under the age of 18 are being married off every day.

The majority of child marriages take place in Southern Asia and sub-Saharan Africa, where five and six year old girls are betrothed, according to the U.N. agency.

The United Nations will work with Archbishop Tutu in calling for all nations to set a mandatory marriage age of no younger than 18.