The United Nations and Iraq signed an agreement Friday aimed at helping the Baghdad government tackle sexual violence in conflict, an issue that made headlines following the capture and rape of Yazidi women by Islamic State extremists in 2014.

Zainab Hawa Bangura, the U.N. special envoy for sexual violence in conflict, and Iraq's Foreign Minister Ibrahim Al-Jaffari, signed the joint communique on the sidelines of the U.N. General Assembly's annual ministerial meeting.

Bangura said that the Islamic State group has inflicted "unspeakable suffering" on civilians, including the targeting of Yazidis and other minorities such as Turkmen Shia, Shia Shabak and Iraqi Christians.

She said the U.N.-Iraq collaboration will especially focus on challenges Iraq faces with accountability for sexual violence and bringing perpetrators to justice. To date, there have been no trials.

Bangura's office said the support envisioned under the agreement will include documenting and collecting evidence of alleged sex crimes, strengthening Iraq's legal framework to better address sexual violence and putting in place procedures for compensating victims.

Bangura recalled a visit to Iraq last year where Yazidi girls described being "inspected like livestock, sold in modern-day slave marked and then repeatedly raped by the fighters who bought them."

Some escaped, she said, but thousands of Yazidis, including women and girls, are still missing.

"I do believe that these crimes amount to war crimes, crimes against humanity, and acts of genocide," Bangura said.

Earlier this week, 23-year-old Nadia Murad, a Yazidi woman who was captured by the IS group in 2014 but escaped, was named a U.N. goodwill ambassador for the Office on Drugs and Crime where she will campaign for "the dignity of survivors of human trafficking." Murad, who said she was raped and prayed for death while in captivity, was accompanied by her British lawyer, Amal Clooney, the wife of actor George Clooney.