With the Syria crisis and tensions over North Korea dominating G8 talks in London today, World Vision is urging foreign ministers to address "forgotten" child victims of rape and sexual violence in conflict.
The Christian aid agency said it would take a concerted international effort to end sexual violence, especially against children, in places affected by war.
According to Senior Child Rights Adviser for World Vision UK, Erica Hall, children represent around half the reported victims of sexual violence in wartime.
"Yet these children are often overlooked in emergency responses and don't get the support they need to rebuild their lives," she said.
World Vision has documented evidence of sexual violence against children in 50 countries including Syria, Mali, Afghanistan, Burma, and the Democratic Republic of Congo.
Perpetrators include soldiers, community members, and even family members who "take advantage of the breakdown of society in times of conflict".
The British Government has pledged to seek "concrete commitments to begin to address the culture of impunity for those who use rape and sexual violence as a weapon of war".
The Foreign Office is backing a new international protocol on the investigation and documentation of sexual violence in conflict, as well as practical assistance in countries where it is occurring.
World Vision said the meetings this week were a crucial starting point, but only the beginning in eradicating the problem.
William Hague and the other foreign ministers meeting for the summit have a "historic chance" to bring about change, said Hall.
"We urge these governments to direct funding into the right places to protect these forgotten children and to prevent needless rapes from happening in future."