UNITED NATIONS — Outgoing U.N. Secretary-General Ban Ki-moon on Tuesday called on all countries to investigate and prosecute cases of human trafficking and said the most vulnerable victims are women, children and refugees caught up in conflict areas around the globe.

Ban, addressing the 15-member Security Council, said extremist groups from the Islamic State to Boko Haram and al-Shabab traffic in persons, especially females, as a weapon of terror and source of revenue.

“We have to fight trafficking for the sake of the victims,” Ban said. “When we do, we will also decrease funding for terrorists – and make everyone safer.”

Ban, whose term ends Dec. 31, spoke as the Security Council considers its first-ever resolution on the topic of human trafficking, which seeks to strengthen the United Nation’s ability to counter the phenomenon.