Washington (AFP) – The United States declared Thursday that the Islamic State group’s slaughter of Christians, Yazidis and Shiites amounts to a genocide and vowed to halt it.

Secretary of State John Kerry made the proclamation after Congress demanded Washington recognize that the group seeks to exterminate religious minorities.

“Daesh is genocidal by self-proclamation, by ideology and by actions, in what it says, what it believes and what it does,” Kerry declared.

“Daesh is also responsible for crimes against humanity and ethnic cleansing directed at these same groups, and in some cases also against Sunni Muslims, Kurds and other minorities,” he added.

The Islamic State group has regularly carried out mass killings of Shiite Muslims, Christians and Yazidis. In June 2014 it seized the formerly cosmopolitan city of Mosul in northern Iraq, placing whole communities under threat of murder, rape or enslavement.

– ‘Existential threat’ –

Already in March last year, UN investigators warned the self-proclaimed caliphate was trying to wipe out Yazidis, members of a pre-Islamic religious minority.

While genocide is a crime under international law, US officials say Kerry’s ruling does not put Washington under any more legal obligation to act.

Instead, they argue, the United States is already doing its utmost to halt the slaughter by leading a 66-nation coalition to “degrade and destroy” the group.  

Kerry said the facts must one day be brought before an international tribunal, and that the United States would do all it could to support an investigation and prosecution. 

He said that through air strikes and support for local forces, the coalition has pushed IS fighters from 40 percent of the territory it once held in Iraq and 20 percent in Syria.

“We’ve degraded their leadership, attacked their revenue sources and disrupted their supply lines, and currently we are engaged in a diplomatic initiative aimed at trying to end the war in Syria,” he said.

Kerry argues Bashar al-Assad’s brutal campaign to cling to power in Syria fuels the chaos that allowed the IS group to seize the east of his country.

He vowed to continue pressing for a negotiated settlement to the broader civil war to allow local forces and the international coalition to focus its fire on the extremist threat.

“My purpose in appearing before you today is to assert that in my judgment Daesh is responsible for genocide against groups in areas under its control including Yazidis, Christians and Shia Muslims,” he said. 

“For those communities the stakes in this campaign are utterly existential,” he said. “So we must bear in mind after all that the best response to genocide is a reaffirmation of the fundamental right to survive.”  

The intensity of the conflict and the IS group’s history of murdering journalists, aid workers and suspected “spies” has made it difficult to document its crimes in great detail.

– Murder and slavery –

But the group has itself issued propaganda videos showing the mass killing of prisoners, and issued its own legal rulings pronouncing that captured non-Muslim women slaves may be raped by its fighters. 

“We’ve not been able to compile a complete record, I think that’s obvious on its face,” Kerry admitted.

“But over the past months we have conducted a review of the vast amount of information gathered by the State Department, by the intelligence community, by outside groups.”

Kerry cited what he said was the August 2015 massacre of hundreds of Yazidi men and older women by the IS group, which trapped tens of thousands more on an exposed mountain without food or medicine.

“Without our intervention, it is clear those people would have been slaughtered,” Kerry said, adding that thousands of Yazidi women and girls had been sold at auction.

Kerry added that the group has executed Christians in northern Iraq and in Libya, where it also has a growing presence, and had sold Christian girls into sexual slavery.

And he cited the murder of hundreds of Shiite Turkmen from minority communities in Iraq, accusing the group of a systematic effort to destroy the cultural heritage of ancient communities.”