Russian President Vladimir Putin warned on Wednesday that "Militants from Iraq and Syria with experience in military operations are actively being drawn" into Afghanistan.

During a video conference with security service chiefs of ex-Soviet states, the Russian president pointed out that "the situation in Afghanistan is not easy."

He added that "It is possible that terrorists may try to destabilize the situation in neighboring states."

Putin has repeatedly warned about members of extremist groups benefitting from political instability in Afghanistan to cross into neighboring countries as refugees.

While Moscow has been cautiously optimistic about the new Taliban leadership in Kabul, the Kremlin is concerned about instability spilling over into Central Asia where it houses military bases. 

In the wake of the Taliban takeover, Russia held military drills with ex-Soviet Tajikistan - where it operates a military base.

Tajikistan's national security chief, Saimumin Yatimov, told in the video conference that he had registered an "intensification" of attempts to "smuggle drugs, weapons, ammunition" from Afghanistan into his country.

While the Taliban has said it does not pose a threat to Central Asian countries, the ex-Soviet republics in the region have previously been targeted by attacks attributed to allies of Afghan extremists. 

Last week the Kremlin's envoy to Afghanistan, Zamir Kabulov, said Russia will invite the Taliban to Moscow for international talks on Afghanistan scheduled for October 20.