"The trend is for deterioration in the situation in Afghanistan, Taliban militants have almost restored their units and systems of rule, they control a significant part of the territory and all this is taking place against the background of an unstable situation in Pakistan," Nikolai Bordyuzha said.
Southern Afghanistan is the stronghold of the radical Taliban movement which was ousted by the U.S.-led coalition from government in the 2001 campaign. The Taliban have intensified attacks on Afghan and foreign troops this year.
Bordyuzha said that efforts introduced by the antiterrorism coalition forces in Afghanistan "unfortunately have not yielded the desired results," adding that the CSTO is ready to continue cooperation with NATO-led forces in the country.
The CSTO is a security grouping comprising the former Soviet republics of Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia, Uzbekistan, and Tajikistan.
NATO's International Security Assistance Force (ISAF) has about 53,000 troops in Afghanistan under a UN mandate to help give security support to the Afghan government and stop the flow of drugs from the country.
Despite the recent deterioration of relations with NATO, Russia continues to support the military alliance's operations in Afghanistan, and has said it shares NATO's concerns over the worsening security situation in the country.