Foley, an American, was beheaded in a video posted Tuesday, after he was abducted in November while reporting on the Syrian conflict for Agence France-Presse.
Interpol Secretary-General Ronald Noble said Wednesday the action by IS "underlines the depths of its depravity as it wages its campaign of terror across Syria and Iraq. This public slaughter of an innocent man has appalled citizens worldwide, and it highlights the ongoing plight of other innocent people across the region at the hands of bloodthirsty terrorists who know neither compassion nor mercy."
He emphasized the need for a multilateral reply against radicals traveling to the Middle East from other countries to engage in warfare, an Interpol statement said.
Noble's comments came as British authorities said it was likely the IS fighter, seen in the video killing Foley, is British.