Thomas Lubanga, 51, was convicted in March of war crimes for enlisting children under 15 in the Democratic Republic of Congo (DRC), in the ICC's first verdict since it started in 2002.
Ocampo said that "The prosecution will request a sentence in the name of each child recruited, in the name of the Ituri region."
"Children are particularly vulnerable," he added. "This crime is of the most serious concern for the international community."
A 37-year-old Congolese woman, testifying on behalf of the defence, earlier told the tribunal that Lubanga's "chief aim, through his actions, was to pacify" the volatile Ituri region. She added that he had been hosting for months nine homeless Lendu children and a homeless Lendu woman in his “Presidency”.
The sentence will be announced at a date yet to be set.
Lubanga, the UPC's founder and commander of its military wing the Patriotic Forces for the Liberation of Congo (FPLC), has been imprisoned in The Hague since 2006.