Moscow has positioned itself as bulwark against potential spillover from Afghanistan into Central Asia, where three former Soviet republics share borders with the conflict-wracked country.

The joint exercises at the Kharb-Maidon training ground just 20 kilometres from the Tajik border with Afghanistan involve 2,500 troops from Russia, Tajikistan and Uzbekistan, Russia's Central Military District said in a statement.

The drills that will continue until August 10 are being held in parallel to joint Russian-Uzbek manoeuvres featuring 1,500 troops in Uzbekistan's Termez near the border with Afghanistan.

Russia maintains military bases in both Tajikistan and Kyrgyzstan, Central Asia's two poorest countries.