The Islamic State-Khorasan (ISIS-K) presents a major predicament for the US amid talks with the Taliban over the withdrawal of troops from Afghanistan.

ISIS-K is fighting the Taliban for supremacy in Afghanistan, conducting deadly attacks on civilians and local security forces.

ISIS-K is connected with the Islamic State's central leadership, and there are concerns it will use Afghanistan as a launching pad for global terrorism — including in the West.

"The US should be very concerned about ISIS using Afghanistan to stage attacks on the West," an expert told Insider. "A withdrawal of US forces reduces our ability to disrupt ISIS's operations in Afghanistan and thereby cedes greater opportunity for ISIS to pursue external operations."

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The Islamic State-Khorasan (ISIS-K) is a growing threat in Afghanistan and parts of Pakistan, staging suicide attacks on civilians and local security forces, as well as battling the Taliban for supremacy in Afghanistan.

There is even concern among national security experts that ISIS-K could launch attacks against the West from its position in Afghanistan.

The US is negotiating with the Taliban to withdraw troops from Afghanistan after 18 years of war; it's also trusting that the Taliban will be able to keep ISIS-K from growing and launching deadlier attacks in the region — or against the Western democracies — which experts say the Taliban is unlikely to be able to do without outside support.

After the US began to withdraw troops from Syria and diplomatic support from Iraq, ISIS began to regroup in those countries — changing tactics and fundraising sources to take advantage of its new landscape.

As troop withdrawal talks between the Taliban and the US drag on, ISIS-K is becoming a pressing threat.

Here's what we know about the extremist group wreaking havoc on the lives of Afghans and complicating US troop withdrawal.