The Daesh terrorist group has been left with as much as $300 million following the loss of its so-called "caliphate" in Iraq and Syria, "with none of the financial demands of controlling territory and population," U.N. Secretary-General António Guterres said in a report released Monday. The report to the Security Council on the threat posed by Daesh warns that the lull in attacks directed by the terrorist group "may be temporary."

Last week, U.N. experts said in another report to the council that Daesh leaders are aiming to consolidate and create conditions for an "eventual resurgence in its Iraqi and Syrian heartlands." It said the current lull in attacks "may not last long, possibly not even until the end of 2019." Guterres said in the new report that while the loss of territory ended Daesh's ability to generate revenue from oil fields, Daesh is believed to be capable of directing funds to support "terrorist acts" within Iraq and Syria and abroad.

It said informal money transfer businesses known as "hawaladars" are the most common method. He said looted antiquities from Iraq may be another source of revenue for Dash and returnees from the conflict said there was a special unit responsible for selling such objects. "Details of antiquities traded and the current location of any stored antiquities are assessed to be known only to [Daesh] leaders," he said. But the secretary-general said Daesh is also encouraging increased financial self-sufficiency throughout its network of supporters and affiliates elsewhere in the Mideast, Africa and Asia.