The report found that in the early stages of the nearly three-year conflict, the Syrian government troops were largely responsible for grave violations against children; then, as the conflict intensified and armed opposition became more organized they committed an increasing number of child abuses.
"The suffering endured by the children in the Syrian Arab Republic since the outset of the conflict, as documented in this report, is unspeakable and unacceptable," Ban said in the report, dated Jan. 27, which was posted online on Tuesday.
While the United Nations has previously accused both sides to the conflict of grave violations against children, this is the first report to the UN Security Council detailing the worsening extent of the problem. It covers the period March 1, 2011 to Nov. 15, 2013.
Ban said that armed opposition groups have recruited and used children in support roles and for combat.
"Of particular concern were cases of recruitment or attempted recruitment of children within refugee populations in neighboring countries. The majority of incidents were related to recruitment by Free Syrian Army-affiliated groups or Syrian Kurdish armed groups," Ban said.