Although celebrations within Iraq have been ongoing for more than a week, the Pentagon waited until this Monday, when Iraqi Prime Minister Haider al-Abadi declared victory, to offer the Iraqi government a tentative congratulation on their victory over the Islamic State in Mosul.

“I announce from here the end and the failure and the collapse of the terrorist state of falsehood and terrorism which the terrorist Daesh announced from Mosul,” Haider al-Abadi said in a speech shown on state television.

Media reports indicating that victory has been within the grasp of Iraqi Security Forces on the ground in Mosul for months have done little to provide a depth of clarity regarding the brutality of the fight faced by U.S. backed fighters in Mosul, nor has it shined a light on the challenges that will remain after ISIS’ defeat, which may be why the Defense Department was conservative in the language it chose when congratulating local forces on their victory.

“While there are still areas of the old city of Mosul that must be back-cleared of explosive devices and possible ISIS fighters in hiding,” Inherent Resolve officials said, “Iraqi forces have Mosul now firmly under their control.”

This statement makes it clear that the effort against ISIS is not yet over, with pockets of fighters potentially remaining, and the distinct possibility that as-yet undiscovered explosives could still claim the lives of coalition fighters.

The global coalition fighting ISIS congratulates Prime Minister al-Abadi and the Iraqi Security Forces on their historic victory against a brutal and evil enemy. Make no mistake; this victory alone does not eliminate ISIS and there is still a tough fight ahead. But the loss of one of its twin capitals and a jewel of their so-called caliphate is a decisive blow,” Army Lt. Gen. Stephen J. Townsend, the Combined Joint Task Force Operation Inherent Resolve commander said in a video released by the Pentagon on Monday.

Iraq’s Prime Minister seems aware that, although his announcement marks the end of the large-scale war effort in Mosul, it does not mark the end of the struggle to root out extremism and make Iraq safe, stable, and secure.

“We have another mission ahead of us, to create stability, to build and clear Daesh cells and that requires an intelligence and security effort, and the unity which enabled us to fight Daesh,” al-Abadi said.