US Secretary of State John Kerry will miss a deadline imposed by Congress to rule on whether ISIS's murders of Christians in Syria and Iraq amount to genocide.
Lawmakers set Thursday as the day on which the State Department would have to confirm whether the US government regards the brutal ISIS persecution of religious minorities as a crime against humanity.
But department spokesman Mark Toner said Wednesday that Kerry was still gathering evidence before making his determination and would miss the deadline — an admission sure to trigger anger on Capitol Hill.
"Given the scope and the breadth of the analysis he's contemplating, he will not have a final decision completed by the Congressionally-mandated deadline tomorrow," Toner said.
"However, this issue is clearly of the utmost importance to him as well as to Congress, and we expect him to reach a decision very soon."
ISIS's vicious treatment of Christians and other non-Muslim religious minorities such as Yazidis — including wholesale killing and rape — is not disputed in Washington.
But the US administration argues that to designate the ISIS campaign as genocide would have practical legal implications and cannot be taken lightly.
This did not satisfy the House of Representatives, which has voted to classify the killings as genocide and demand that the administration do so, too.
"What more does Secretary John Kerry need to see and hear in order to call these atrocities for what they are?" House speaker Paul Ryan said.
"This is genocide, plain and simple. The House has spoken very clearly on this. And we all continue to pray for the persecuted."
Toner insisted that the State Department respects the right of Congress to demand a decision, but argued "we need some additional time, a matter of a few days or a week or so in order to reach what we believe is a more fact-based, evidence-based decision."
The Obama administration has come under strong criticism for its perceived flip-flopping on ISIS and Syria. In both August 2012 and April 2013, President Barack Obama declared that the use of chemical weapons in Syria would be a "red line" to which he would considering responding with force.
After it was found that forces loyal to Syrian dictator Bashar al-Assad did, in fact, use chemical weapons on civilians, the White House backtracked from his earlier threats.
Obama also promised numerous times that he would not put "boots on the ground" in Syria, only to send Special Forces soldiers to the country last October.