Retaking the Iraqi city of Mosul from the Islamic State (ISIS/ISIL) will only push the jihadist group to other parts of the war-ravaged country, a Kurdish intelligence official predicted during an interview with Reuters.

“Mosul will get taken. … I think it is the asymmetric warfare that we need to be worried about,” Lahur Talabany, a senior figure in Kurdistan’s counter-terrorism efforts, told Reuters, noting that once Iraqi forces push the terrorist group out of the city, “it will switch tactics to wage an insurgency from mountains and deserts.”

“Our jobs will become much more difficult. The army will take a rest a little, but it will be the job of security forces that will become more difficult,” he also said, later adding, “Their plans are to start up some sort of asymmetric warfare — against the region and globally. Also, we will see lone-wolf attacks pop up here and there in the region.”

In July 2016, FBI Director James Comey warned that defeating ISIS could lead to an increase in terrorist attacks in the United States and other Western nations.

The Kurdish intelligence official “also expressed concerns that another group similar to the Sunni Muslim Islamic State could emerge to menace Iraq again if political leaders fail to secure reconciliation between sects,” reports Reuters.

A U.S.-backed alliance primarily comprised of Iraqi government forces, Kurdish Peshmerga troops, and Iran-allied Shiite militias has been fighting to recapture Mosul since mid-October 2016.

So far, the Iraqi troops and their allies have liberated eastern Mosul.

The Pentagon has described Mosul as the last major stronghold in Iraq.

In the last weeks of former President Barack Obama’s administration, then-Secretary of Defense Ash Carter acknowledged that U.S. forces would be needed in Iraq after Mosul falls.

“It’ll take some time to consolidate Iraqi security, even after the fall of Mosul, which will occur — like the defeat of ISIL will occur,” Carter told reporters in January. ”But there will be other cities and towns in Iraq where the government’s control will need to be secured. And there will be an ISIL tendency to go underground and to go to more isolated regions and continue to try to mount operations, and that’ll require a sustained effort. And I think the United States and the international coalition, everybody’s realistic about that.”

Reuters learned from the Kurdish intelligence official that ISIS may seek shelter in the Hamrin mountains located in northeastern Iraq and that the location could allow the terrorist group to attack several provinces.

Echoing Carter, the Kurdish official said, “You have to try and find them when they go underground, you have to try and flush out these sleeper cells. There will be unrest in this region for the next few years, definitely.”