U.S. Secretary of State John Kerry said Thursday that the Islamic State group's attacks on Shiite Muslims, Christians and Yazidis in Iraq and Syria constitute genocide. This is the first time that the United States has declared a genocide since Darfur in 2004.

"My purpose here today is to assert in my judgment, [ISIS] is responsible for genocide against groups in areas under its control, including Yazidis, Christians and Shiite Muslims," he said in a news conference at the State Department. "Without our intervention, it is clear that those people would have been slaughtered."

The House of Representatives on Monday unanimously passed a resolution labeling the ISIS atrocities against Christian groups in Syria and Iraq "genocide," a term the State Department had been reluctant to use about the attacks and mass murders by the terror group until now.

The State Department had until Thursday to decide whether it would issue a genocide designation on the militant group.