Iraq asked for international help on Wednesday to collect and preserve evidence of crimes by Islamic State militants and said it is working with Britain to draft a United Nations Security Council resolution to establish the investigation.
Britain, international human rights lawyer Amal Clooney and Nadia Murad, a woman from the Yazidi religious minority who was enslaved and raped by Islamic State fighters in Mosul, have been pushing Iraq to allow a UN inquiry.
The 15-member Security Council could have established an inquiry without Iraq's consent, but Britain wanted Iraq's approval in a letter formally making the request. Iraq sent the letter, seen by Reuters, on Monday.
"We request assistance of the international community to get benefited from international expertise to criminalize Daesh terrorist entity," wrote Iraq's foreign minister Ibrahim al-Jaafari in the letter, which was translated from Arabic.
Daesh is another name for Islamic State, which is also known as ISIS.
Britain's mission to the United Nations said on Twitter that it was working with Iraq on a draft resolution. It was not immediately clear when it could be put to a vote in the council.