Russian President Vladimir Putin said that battle-hardened militants are actively entering Afghanistan and the situation is not easy, Khaama Press reported.
The President made the remarks while addressing a virtual conference of the security service chiefs of the former Soviet states.
Putin apparently meant by Islamic State (IS) fighters the ones that have not been taken seriously by the Taliban.
IS is not believed to be a big threat to the de-facto government in Afghanistan because the affiliated group, IS-K does not have international or regional support.
Putin said that it is possible that the extremists might destabilize the situation in the neighbouring countries and might even seek direct expansion.
Though the Kremlin has been optimistic about the Taliban leadership in Kabul, it is concerned about instability spilling over into Central Asian countries, the report said.
In the meantime, the Islamic Emirate of Afghanistan has repeatedly said that there will not be any threat posed from their soil to any country.
The statements of the Russian President come as Moscow is preparing to host an international conference and the Taliban will also be invited.
The international talks are due to take place on October 20.