The Islamic State (IS) have expanded their recruitment efforts to war-torn Afghanistan, where Taliban members and men in impoverished families are considered prime candidates for membership. 

The terrorist organisation allowed CNN's cameras to film their recruitment session, exposing the methods they use to attract jihadists.

"Jihad is now obligatory not only in Afghanistan, but also in many other places in the world," the Afghan recruiter told his audience.

"The Christians and Jews have not only attacked Afghanistan, but they have also attacked Muslims in Syria, Iraq and Palestine. So jihad is obligatory on us in these places."

Some attendees were drawn to the ideological aspect of joining the extremist Muslim group. 

"My aim is to fight infidels," one man said. "In Syria, or if they ask me to in Afghanistan, I will."

Others considered joining because IS provides money and housing to their fighters. 

"I definitely need the money," an attendee admitted, "but will stay here and hope peace comes." The man hoped to attend college instead of fighting alongside the militants. 

IS has waged an increasingly deadly campaign across Iraq and Syria since 2011, when the US withdrew from the area. Thousands have been killed, some on graphic video, and whole populations have been persecuted by the terrorists. 

Afghan President Ashraf Ghani explained why IS is becoming more attractive to his citizens. 

"The reason it's happening is because (the) collapse of Yemen, Syria, Iraq has created an environment where instead of one weak link in the interrelated system of states, now there are wider spaces," he told CNN's Fareed Zakaria."

"They have - it's one of the most ... well-financed organisations. And the techniques are spreading."

The splintering of the Taliban also created a void that IS is trying to fill. A senior US official said they, and other countries, are "keeping a very close eye on" the group's recruitment activities. 

"Afghanistan government is concerned. Pakistan government is concerned," he revealed.