President Trump said he expects to announce the final defeat of ISIS' so-called "caliphate" within the next week. In late 2014, ISIS held major cities throughout Iraq and Syria, but U.S. officials now say the group has lost more than 99 percent of that territory.

The territorial defeat of the terror group may now be down to just a matter of days, with the U.S.-led coalition and its allies advancing on the last sliver of territory still under ISIS control. But as CBS News correspondent Charlie D'Agata reports from the front line in eastern Syria, with the militants concentrated in such a small area, all the fighting that's left to do is at extremely close range. The CBS News team had to run from a suspected ISIS rocket as the fighting raged this week.

An airstrike slammed into an ISIS target much closer than anyone expected. It was followed immediately by a whirring noise, feared to be the sound an incoming ISIS mortar that flew right over their heads, sending everyone scrambling. Kurdish soldiers eventually shouted for everyone to break cover and run to a safer place.

Reaching that last strip of ISIS-held territory meant a sprint through the desert to avoid ISIS ambushes to an abandoned home, which is now a forward operating base for the U.S.-backed Syrian Democratic Forces (SDF). From the roof, D'Agata could get a glimpse of life in what's left of the so-called caliphate as it faces an inevitable end. He could see men on motorcycles and women in black burkas. They are now surrounded on all sides.

The sounds of jets roaring overhead followed by two airstrikes confirmed that the fight is not over yet -- though it will be soon. It's an end, however, that many people on the ground fear will speed up the departure of the 2,000 U.S. troops who fought beside soldiers like SDF commander Adnan Afrin.

Afrin is worried about what might happen after American forces leave. "We fought together," he said, adding that he felt President Trump's decision to pull U.S. troops out of the country, "wasn't a wise decision. It's a decision to leave halfway through."

By "halfway through," the commander said he meant what comes after ISIS loses that last pocket of territory.

Afrin said the group has already established an underground network of terror cells of hardened fighters, preparing to regroup, and strike back.