The International Criminal Court's prosecutor says the Islamic State terror group has committed "crimes of unspeakable cruelty" in Syria and Iraq, but she does not have jurisdiction to open an investigation.

Fatou Bensouda said in a written statement Wednesday that "the jurisdictional basis for opening a preliminary examination into this situation is too narrow at this stage."

The court does not have jurisdiction because neither Syria nor Iraq is a member of the court and the United Nations Security Council has not asked for an investigation.

Bensouda says she made her comments after repeatedly being asked whether she can prosecute IS atrocities.

She says that nations that are not members of the court, or the Security Council, could grant her jurisdiction, but she can't influence that decision.