Pentagon spokesman John Kirby said on Tuesday that the Pentagon will continue to conduct drone strikes against ISIS-K terrorists and other targets within Afghanistan when necessary, despite the withdrawal of the US military from the country.

"We have the capability from an over the horizon perspective of ensuring our national security interests are protected and defended," Kirby said during an interview with NPR. "And what I would tell you, without getting into hypotheticals or speculating about future operations, we're going to continue to maintain those capabilities and use them if and when we need to."

Kirby affirmed in the interview that protracted US military action in Afghanistan would not occur.

"The military mission in Afghanistan is over, and that includes the conclusion of the 20-year war that we'd been fighting there. The president was very clear that he wanted to end this war. And we have ended it," he stressed, adding the Pentagon does "not assess that there is a significant threat to our national security emanating from Afghanistan right now."

"But we're not going to drop the ball here. We're not going to take our eye off of it. We have robust over the horizon capabilities. We're going to continue to use them where and when we need to," Kirby added.

The final American troops departed Kabul’s airport on Monday, nearly 20 years after the September 11, 2001 attacks.

Islamic State-Khorasan is the terrorist group which claimed last week’s suicide bombing at Kabul airport, in which 13 US troops were killed.

On Tuesday, US President Joe Biden defended his decision to pull American troops out of Afghanistan but also warned ISIS-K that “we are not done with you yet.”