Long-term solutions to end female genital mutilation and child marriage are essential to ensure progress towards ending harmful practices, the British agency, Christian Aid says.
It said better opportunities for girls and women, supporting survivors and protecting girls at risk were key areas to be addressed at Tuesday's Girl Summit .
The event was hosted by the UK Prime Minister, David Cameron, and jointly organized by Britain's Department for International Development and UNICEF.
Cameron called for a global ban on female genital mutilation and child marriage at the launch of the first U.N.-backed Girl Summit.
"Our aim is to outlaw FGM and child marriage everywhere for everyone," he said.
The prime minister announced that parents in Britain subjecting their daughters to genital mutilation (FGM) will be prosecuted.
One of the speakers at the event was Malala Yousafzai, the Pakistani schoolgirl who was shot in the head by the Taliban, but who recovered and campaigns for girls' education.
"We should have the right to change traditions and we should make the changes. We ask that there be no more FGM or child marriage," Malala said.
"We should not be followers of traditions that go against human rights."
Christian Aid is part of the Geneva-based ACT Alliance that fight poverty and seeks justice for those who need it.
Chiara Capraro, Christian Aid's policy advisor on gender, said, "We welcome the Summit and DfID's (the international development department's) ambition to tackle these issues and the recognition of the key role of faith-based and civil society organizations in the fight against both practices.
"'We want to remind political and faith leaders that this commendable ambition needs long-term commitment and investment to address the damaging social and cultural norms that reinforce these practices.
"Working with communities, education and engaging with religious and traditional leaders is essential."
Christian Aid wants to see the ending of female genital mutilation and child, early and forced marriage included in the new Sustainable Development Goals set to replace the current U.N. Millennium Development Goals when they expire in 2015.
The Christian agency welcomed the inclusion of a target on harmful practices within a recently agreed report from the U.N.'s Open Working Group on SDGs.
It urged world leaders to take this forward as part of a specific goal addressing the rights of women and girls.
Such a move could be a significant step forward in enhancing deepening global commitment to gender equality.
Christian said approximately 140 million girls and women are currently living with the consequences of FGM globally, of whom 92 million live in Africa. Worldwide, more than 60 million girls are child brides, forced into marriage before the age of 18.