UNITED NATIONS - UN Secretary-General Ban Ki-moon Wednesday called for protecting girls against child marriage on the inaugural day of the International Day of the Girl Child.

"Globally, around one in three young women aged 20 to 24 - approximately 70 million - were married before the age of 18," Ban said in a message.

"Despite a decline in the overall proportion of child brides in the last 30 years, the challenge persists, particularly in rural areas and among the poorest," he said. "If present trends continue, the number of girls who will marry by their 18th birthday will climb towards 150 million in the next decade."

On December 19, 2011, the United Nations General Assembly adopted a resolution to declare October 11 as the International Day of the Girl Child, to recognize girls' rights and the unique challenges girls face around the world.

This year marks the first anniversary of the day with the theme of "my life, my right, end child marriage."

Ban noted that child marriage divorces girls from opportunity. It also jeopardizes health, increases exposure to violence and abuse, and results in early and unwanted pregnancies.

The secretary-general pointed out that education for girls is one of the best strategies for protecting them against child marriage.

With the access to school, girls can build a foundation for a better life for themselves and their families, he said.

"I urge governments, community and religious leaders, civil society, the private sector, and families to promote the rights of girls, including through the relevant conventions, the Beijing Declaration and Platform for Action, and the Program of Action of the International Conference on Population and Development," Ban said. "Let us do our part to let girls be girls, not brides."