REPUBLIKA.CO.ID, NEW YORK -- Up to 10 million people in Iraq, including vulnerable people in areas currently controlled by the Islamic State (IS/ISIS), will require some form of humanitarian assistance by the end of 2015, UN spokesman Stephane Dujarric told reporters here Friday.

Some 3.2 million people in Iraq have fled their homes in multiple waves of internal displacement since January 2014 and up to now, an estimated 8.6 million people need humanitarian support, Dujarric said at a daily news briefing here.

"The crisis has accelerated since last year, cholera has broken out, basic services are not functioning, and food rations and water supplies have been decreased in part due to lack of donor support," he said.

The UN Humanitarian Response Plan requesting some 500 million U.S. dollars is only 40 percent funded, according to the spokesman.

The IS fighters swept through north Iraq last June, but their advance was contained by Shi'ite militias and Kurdish peshmerga fighters, backed by U.S.-led air strikes, reports said.