Tajikistan on Wednesday called on members of a Russian-led military bloc to help it deal with security challenges emerging from Afghanistan, hours after Moscow pledged to defend its regional allies affected by the unrest, Reuters reported. 

The security situation in Afghanistan has rapidly deteriorated as foreign troops withdraw after 20 years. 

More than 1,000 Afghan government troops were reported to have fled north into Tajikistan this week as the Taliban seized dozens of districts in the past two months. 

In an appeal to the Collective Security Treaty Organisation (CSTO), which includes Russia and five other ex-Soviet states, a Tajik official said his country could not handle the instability at its border without external assistance, the Reuters said. 

"Given the current situation in the region, as well as the remoteness and mountainous terrain of some parts of the border with Afghanistan, dealing with this challenge on our own seems difficult," the RIA news agency quoted Hasan Sultonov, the Tajik representative at CSTO, as saying. 

Sultonov's comments came after Russian Foreign Minister Sergei Lavrov said Moscow was ready to use its military base in Tajikistan, one of its biggest abroad, to ensure the security of its allies in the region. 

"We are closely watching what is happening in Afghanistan where the situation has a tendency to swiftly deteriorate including against the backdrop of the hasty exit of American and other NATO troops," Lavrov said. 

"We will do everything we can, including using the capabilities of the Russian military base on Tajikistan's border with Afghanistan, to prevent any aggressive impulses towards our allies," Lavrov said. 

Russian President Vladimir Putin on Monday told Emomali Rakhmon, the president of Tajikistan, that Moscow would help the impoverished former Soviet republic contend with the fallout from NATO's exit from neighbouring Afghanistan if needed. 

Rakhmon has ordered the mobilisation of 20,000 military reservists to bolster his country's border with Afghanistan after more than 1,000 Afghan security personnel fled across the frontier in response to Taliban militant advances. 

Also, Russia is prepared to activate a military base in ex-Soviet Tajikistan against advancing Taliban forces on its southern border as US troops finalize their pullout from neighboring Afghanistan, its top diplomat said Wednesday, The Moscow Times reported. 

Tajikistan is host to more than 6,000 Russian servicemen deployed to the Russian Ground Forces’ 201st military base, one of Russia's few military sites on foreign soil.