Last month, a security expert told UK media that Daesh (ISIS)* leader Abu Bakr al-Baghdadi may have moved to Afghanistan following the recent elimination of the group's 'caliphate' in Iraq and Syria.

An Afghanistan-based US intelligence official believes Daesh, not the Taliban, is currently the most serious threat to US and European security emanating from the war-torn Central Asian country.

"This group is the most near-term threat to our homelands from Afghanistan," the official said, speaking to AP. "The core mandate is: You will conduct external attacks…That is their goal. It's just a matter of time. It is very scary," the official noted.

According to the official, the recent string of deadly car and suicide bombing attacks in the Afghan capital of Kabul for which Daesh has claimed responsibility were just "practice runs" for even larger-scale attacks planned for Europe and the US.

The official did not clarify whether US or European intelligence had any idea about how the Afghanistan-based jihadists planned to make their way westward, although tens of thousands of Afghan refugees are thought to have entered the EU in recent years amid the migrant crisis which began in 2015.

Daesh's Afghan presence has grown dramatically amid the decline of the terror group's activities in Iraq and Syria. Ajmal Omar, a member of the provincial council of the Nangarhar Province in eastern Afghanistan, estimates that "thousands" of militants have now set up shop in his region.

"Right now in Kunar, the right side of the road is Taliban, the left side is Daesh and the government is in the middle," he said. "When they began in Afghanistan they were maybe 150 Daesh, but today there are thousands and thousands," he added.

The US and its NATO allies have struggled to gain and keep control over Nangarhar province since the 2001 invasion, with the mountainous province recently becoming home to violent clashes between local Taliban militants and the incoming Daesh terrorists struggling for control.

On Tuesday, Afghan media reported that some 13,300 families were displaced in fighting between the militant groups over the past month and a half, forcing them to settle on the outskirts of the city of Jalalabad. One resident said Daesh had threatened to kill civilians unless they left their homes.

Daesh's Afghan affiliate is known as 'Khorasan Province', with its area of operations said to include Afghanistan, Pakistan and other areas of South Asia including India. In addition to recruits from the Taliban, the regional affiliate is thought to consist of militants from Arab countries, India, Russia's Chechnya, Bangladesh and radicalised Uighurs from western China.

Commenting on Daesh's acquisition of "key" Afghan terrain from which they can stockpile cash, weapons and equipment and "plan, train, stage, facilitate and expedite attacks," the intelligence official urged the US and its allies to commit to a more aggressive "counterterrorism" strategy in the country.

Earlier this month, the US envoy negotiating with the Taliban promised to hold fresh talks with the group in Doha, Qatar following a month-long lull. Despite continued fighting between Taliban forces and the Afghan government, the two sides have made efforts to sit down for negotiations to bring the nearly 18-year-old war in Afghanistan to an end.

*A terrorist group outlawed in Russia and many other countries.