"It's not an investigation, it's not a prosecution, it's just collecting information," Bensouda told Sputnik Thursday evening, on the sidelines of an event at the Council on Foreign Relations, a New York-based think tank.
The chief prosecutor stressed that the information needs to be assessed carefully before any prosecutions can be launched.
"Already we had the policy of [prosecuting those] most responsible [for war crimes]. So you would assume that we only have to look at the most responsible amongst the ranks of ISIS [IS]. But the recent strategic plan of looking at notorious and mid-level and then moving up gradually to the most responsible is possible," Bensouda explained.
IS, which has been fighting the Syrian government since 2012, having also extended its attacks to Iraq, is well-financed and draws fighters from many regions, including Europe. A UN commission has accused it of war crimes and crimes against humanity for such brutal tactics as killing, enslavement, rape and sexual slavery.
The ICC has no jurisdiction in Iraq or Syria, but Jordan, Tunisia and European countries are members of the court and their nationals are subject to prosecution by the Netherlands-based tribunal under certain circumstances.
With headquarters in The Hague, the ICC is the world's only independent permanent tribunal to try cases of genocide, war crimes and crimes against humanity.
