The White House on Thursday said it was ready to support an investigation by the International Criminal Court into alleged genocide carried out by the Islamic State group in Syria and Iraq.
"The United States will cooperate with independent efforts to investigate genocide," said spokesman Josh Earnest, adding that the administration is willing to support the ICC in gathering evidence.
The United States declared earlier Thursday that the Islamic State group's slaughter of Christians, Yazidis and Shiites in Iraq and Syria amounts to a genocide and vowed to halt it.
"The ICC is typically the organization that would take a look at this, and given the judgment that Secretary (of State John) Kerry has made, the United States would be supportive of that effort, both rhetorically, but also in a tangible way as well," said Earnest.
"The United States will support efforts to collect documents, preserve and analyze evidence of atrocities and the United States will do all we can to ensure perpetrators of these atrocities are held to account and brought to justice."
The United States is not party to the ICC, but President Barack Obama's administration has introduced a policy of working with the court.